PP Systems EGM-4 Operator's Manual

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Page 1

PP Systems

110 Haverhill Road, Suite 301

Amesbury, MA 01913 U.S.A.

Tel: +1 978.834.0505

Fax: +1 978.834.0545

EGM-4 Environmental Gas

Monitor For CO

Operator’s Manual

Version 4.19

For Firmware (EPROM) Version 1.46 and Greater

14 February 2013

Email: [email protected]

Web Site: http://www.ppsystems.com

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This page left intentionally blank for printing purposes.

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Table of Contents

Table of Contents ........................................................................................... 3

Preface ............................................................................................................ 5

System Calibration ........................................................................................ 5

User Registration .......................................................................................... 5

Warning Notice ............................................................................................... 6

Condensation Risk ........................................................................................ 6

PP Systems’ Contact Information ................................................................. 7

Technical Specification ................................................................................. 8

Introduction .................................................................................................... 9

Measurement Principle ................................................................................. 9

Getting Familiar With The EGM-4 ............................................................... 10

Front Panel ................................................................................................................... 10

Environmental Sensor I npu ts (I/O Por ts ) .................................................... 12

Analog Output ............................................................................................. 13

Current Output ............................................................................................ 13

RS232 Port ................................................................................................. 13

Soda Lime Absorber Column ...................................................................... 13

Soda Lime ........................................................................................................................ 14

Keypad ........................................................................................................ 14

LCD Display ................................................................................................ 14

Gas Ports .................................................................................................... 14

Battery ........................................................................................................ 14

Powering The EGM-4 With Internal 12V NiMH Battery ............................... 14

CHARGING THE INTERNAL 12V NiMH BATTERY ........................................................ 15

Charge Cycle and LED Indications for 12V NiMH Battery Charger ................................. 15

Charge Socket ............................................................................................ 15

Power Supply/Charger ..................................................................................................... 15

Power Switch .............................................................................................. 16

Operation ...................................................................................................... 17

Main Menu .................................................................................................. 19

1REC .......................................................................................................... 19

Stand Alone CO2 Analyzer (Probe Type 0) ...................................................................... 20

Measurement Mode Display Structure ............................................................................. 21

Changing Plot Number ..................................................................................................... 22

Environmental Monitor (Probe Types 1-6 and 10) ........................................................... 22

PP Systems Environmental Sensor Conversions: ........................................................... 23

Steady State Porometer (Probe Type 7) .......................................................................... 23

Closed System Soil Respiration (Probe Type 8) .............................................................. 24

Use of our PAR Sensor with SRC-1 Soil Respiration Chamber ...................................... 24

Oxygen (Probe Type 9) .................................................................................................... 27

Open System Soil Respiration (Probe Type 11) .............................................................. 27

Calculation Of Fluxes For CFX And CPY Chambers ....................................................... 29

2SET ........................................................................................................... 30

1EGM ............................................................................................................................... 30

Probe Types ..................................................................................................................... 30

Probe Setting Override ..................................................................................................... 31

2Z ..................................................................................................................................... 31

Changing the Zero Type ................................................................................................... 31

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Table of Contents

Changing the Zero Time ................................................................................................... 32

3PMP ................................................................................................................................ 32

Static Sampling with the EGM-4....................................................................................... 32

4AV ................................................................................................................................... 32

5RECD ............................................................................................................................. 33

6ALM ................................................................................................................................ 33

Setting the Low CO2 Alarm Setpoint ................................................................................ 33

Setting the High CO2 Alarm Setpoint ............................................................................... 34

7VOUT .............................................................................................................................. 34

3CAL ........................................................................................................... 35

Connecting Calibration Gas To The EGM-4 .................................................................... 35

4DMP .......................................................................................................... 36

Screen Display ................................................................................................................. 36

Data Dump ....................................................................................................................... 37

Transferring Stored Data Using The Windows® Based Software Program ..................... 37

Logging Data .................................................................................................................... 38

Record Structure .............................................................................................................. 38

Data Structure Based On Probe/Sens or s ........................................................................ 39

Error Cod .......................................................................................................................... 40

es ...................................................................................................................................... 40

EGM Serial Outputs .................................................................................... 41

5CLR ........................................................................................................... 41

6CLK ........................................................................................................... 42

Diagnostics and Initialisation ..................................................................... 43

Diagnostics ................................................................................................. 43

Initialisation ................................................................................................. 43

Maintenance ................................................................................................. 44

Soda Lime Absorber Column ...................................................................... 44

Soda Lime ........................................................................................................................ 44

MATERIAL SAFETY DATA FOR SODA LIME ................................................................ 45

Servicing The EGM-4 .................................................................................. 46

Fuse .................................................................................................................................. 46

Inside the EGM-4 .......................................................................................................... 47

Infrared Source ................................................................................................................. 47

Checking EGM-4 Raw A/D Readings .............................................................................. 48

EPROM ............................................................................................................................ 48

ZERO Valve...................................................................................................................... 49

12V Lead Acid Battery ...................................................................................................... 49

12V Lead Acid Battery Specif ication ................................................................................ 49

Removing The 12V Lead Acid Battery ............................................................................. 49

12V NiMH Battery ............................................................................................................. 50

12V NiMH Battery Specificatio n ....................................................................................... 50

Removing The 12V NiMH Battery .................................................................................... 50

Air Sampling Pump ........................................................................................................... 51

Replacing The Air Sampling Pump .................................................................................. 51

Cleaning The Air Sampling Pump .................................................................................... 51

In-Line Filter Assembly (Hydrophobic) ............................................................................. 52

Consumables and Spares for EGM-4 ......................................................... 53

User Notes .................................................................................................... 54

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Preface

It is extremely important that you take the time to review this operator’s manual prior to installation and operation of the EGM-4 CO caused which is not c overed under our norm al warranty polic y. This operator’s manual is

relevant to all EGM-4’s running firmware (EPROM) version 1.30 and higher.

System Calibration

• This product is shipped as a factory calibrated system. System calibration is not required upon receipt from our factory.

• Familiarization with the doc umentation and cal ibration procedures is required prior to future recalibration. See section 3CAL on page 35 of this manual.

• All calibration related questions may be directed directly to PP Systems at:

Telephone: +1 978.834.050 5

Fax: +1 978.834.0545

Email: [email protected]

Gas Analyzer. Otherwise, damage may be

User Registration

It is very important t hat ALL new customers register with us to ens ure that our user’s list is kept up to date. If you are a PP Systems ’ user, please regis ter yourself electronicall y on our web site at http://www.ppsystems.com/user_registration2.htm .

Only REGISTERED users will be al lowed access to o ur protected “U sers” section of our web site. This section will contain important product information including hardware/software updates, application notes, newsletters, etc.

Thank you in advance for your cooperation.

The warranty excludes all defects in equipment

caused by incorrect installation, operation or

maintenance, misuse, alteration, and/or

accident.

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Warning Notice

Our in-line filter as sembly

Warning Notice

This instrument must not be used in situations where its failure could result in injury or death. For applications where failure of this instrument to function correctly would lead to consequential damage, the Analyzer must be checked for correct operation and calibration at intervals appropriate to the criticality of the situation.

This manual is provi ded to hel p you instal l and operat e the equipment. Every effor t has been made to ensure that the information c ontained in this manual is accurate and complete. PP Systems does not accept any liability for losses or damages resulting from the use of this information. PP Systems' equipment warranty is limited to replacement of defective components, and does not cover injury to persons or property or other consequential damage. This manual, an d the information containe d in it, is copyright to PP S ystems. No part of the manua l may be copied, stored, transm itted or reproduced in any wa y or by any means including, but not l i mited to, photocopying, p h otogr a phy, magnetic or other mechanical or electrical means, without the prior written consent of PP Systems.

The EGM-4 is covered under warranty for one complete year, parts and labour included. This, of course, is provide d that the equipm ent is properl y installed, operat ed and mainta ined in accordance with writte n instructions (i.e. Operator's Manual). The warranty exclud es all

defects in equipment caused by incorrect installation, operation or maintenance, misuse, alteration, and/or accident.

If for some reason, a f ault is c overed under warr ant y, it is the respo nsib ilit y of the c ustom er to return the goods to PP Systems or an authorised agent for repair or replacement of the defective part(s).

Condensation Risk

If condensation occurs in the analysis s ample line, fr ee water m ay enter the analyzer caus ing serious damage which will res ult in a very expensive repair. Therefore, it is critical that you periodically inspect th e pipeline t o be sure t hat conde nsed water does not enter the anal yzer. If the EGM-4 is supplied on its own, we do NOT supply any external filters. If the EGM-4 is used in conditions where there is risk of condensation or water in the sample line, (i.e. when used with the SRC-1, CPY-2, CPY-4 or CPY-3 chambers for measurement of soil/canopy assim ilation, we strongly recommend f itting our hydrophobic filter to the “Gas In” port as shown below. Our h ydrophobic filter ass embly (Part No. 100 45-1) is supp lied with all SRC-1’s, CPY-2 ’s, CP Y-4’s and CPY-3 ’s. Al l EGM-4 c ustomers can pur chase this filter from PP Systems (Part No. 10045-1) at any time if required. In additio n, when this filter is used, it must be checked regularly and replaced as when dirty or wet. Otherwise, blockage can occur.

(Part No. 10045-1)

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Warning Notice

For maintenance instructions, see In-Line Filter Assembly (Hydrophobic) on page 52.

Very Important

If there is any risk of of water entering the EGM-4, you m ust protect the instrument b y using an external 3 µm hydrophobic filter (Part No. 10045-1) or water drop ou t trap. We strongly recommend using 3 µm filters as any other size may cause damag e to the pump. If a water drop out trap is used, it should be regularly checked and emptied as required.

If condensation persis ts, it is then recomm ended that a PP Systems’ water vapor equ ilibrator (Part No. 10049-1) is used (see picture below). This is constructed fr om a material t hat is very permeable to water vapor but impervious to CO pipe at the sampling point, the water vapor concentra tion of the analysis air will be brought close to ambient.

. If this is placed in-lin e in the analysis

Part No. 10049-1 Water Vapor Equilibrator fitted to top of EGM-4

The problem may also be avoided by putting a suitable water drop out trap or drier in the same position. Drierit e (anhydrous Calcium Sulphate) is suitable. DO NOT us e Silica Gel, which also absorbs CO

Please note that any method used to remove excess water from the analysis sample will render any humidity measurement incorrect.

If you have any questions whatsoever with regards to possible condensation risk, contact PP Systems (See PP Systems’ Contact Information on page 7).

PP Systems’ Contact Information

PP Systems 110 Haverhill Road, Suite 301 Amesbury, MA 01913 U.S.A.

Tel: +1 978.834.0505 Fax: +1 978.834.0545 Support: [email protected]

Sales: [email protected]

Service: [email protected]

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Web Site: http://www.ppsystems.com

Analysis Method

Non-dispersive infrared with microprocessor control and linearisation.

Measurement

0-1,000 ppm (µmol mol-1)

Measurements are automatically corrected for temperature and pressure.

Accuracy (CO2)

< 1% of span concentration over the calibrated range, but limited by the accuracy of the calibration gas mixture.

Linearity

< 1% throughout the range.

Stability

Automatic Zero at regular intervals. It corrects for sample cell changes.

Sample Pump

Integral DC pump operating at a flow rate of approximately 350 ml/min. Pump can be disabled for static measurements on demand.

Gas Flow Rate Through Analyzer

Minimum flow rate: 200 ml/min Maximum flow rate: 400 ml/min

Environmental Sensor Interface

Two inputs available for use with external sensors (humidity, temperature, PAR, oxygen, soil respiration, canopy assimilation, etc.).

Air Filter

Filtered sample line (hydrophobic)

Calibration

Default value preset in factory (Built-in Initialization). Automatic calibration via keypad if required.

CO2 Control

High and low set points

Alarm

Audio Alarm

Real Time Clock

Accuracy > 1 minute per month at 25˚C, operating temperature 0-70˚C. Automatic correction for month end and leap years.

Recording

Manual (by keypress) or automatic at user selected intervals between 1 and 250 minutes.

Keypad

Custom, tactile keypad

Data Storage

512 K Battery backed RAM (1,000 records).

Response Time

Display/analog output: 1.6 seconds

Analog Output (CO2 only)

4-20 mA, 0-1 V, 0-2 V, 0-3 V, 0-4 V, 0-5 V (Linear)

Digital Output (RS232)

9600 baud/8 data bits, 1 start bit/2stop bits/no parity ASCII Format

Display

High contrast 2 x 16 character LCD.

Power Supply

12 V, 2.0 Ah Rechargeable Lead Acid Battery providing up to 4 hours

sensors/accessories.

Gas Connections

Two barbed fittings (inlet and exhaust) for 1/8” (.125”) ID tubing.

Housing

High impact, aluminum enclosure.

Operating Environment

-5o C – 50

C, non-condensing. In dirty or high humidity environments,

external air filtration is required.

Dimensions

18 cm (W) x 21.5 cm (H) x 6.3 cm (D)

Weight

1.9 kg

Technical Specification

Range (CO2)

0-2,000 ppm (µmol mol-1) 0-5,000 ppm (µmol mol-1) 0-10,000 ppm (µmol mol-1) 0-20,000 ppm (µmol mol-1) 0-30,000 ppm (µmol mol 0-50,000 ppm (µmol mol-1) 0-100,000 ppm (µmol mol-1)

-1)

contamination, source and detector ageing and pre-amplifier gain

continuous use or 12V NiMH rechargeable battery providing up to 8 hours continuous use. Longer times available with external 12V battery. Battery life may be reduced when EGM-4 is used with add-on

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Introduction

PP Systems is c ontinuously updating its products a nd reserves the right to amend pr oduct specifications without notice.

Introduction

The EGM-4 CO Ah lead acid rechargeable battery providing up to 4 hours continuous use or 12V NiMH rechargeable batter y providing up to 8 hours continuous use. For extended operatio n in the field, PP Systems can also provide an external power supply cable that will allow you to connect up to an externa l 12 V battery. If interested, please contact P P Systems (See PP

Systems’ Contact Information on page 7).

The EGM-4 is a high precision instrument for use in CO greenhouses, environment control rooms, nur ser ies and lab or atori es . Long ter m stability and accuracy is ensured as a result of our unique “Auto-Zero” technology. The EGM-4 also features inputs for additional sensors for measurement of humidity, temperature, PAR, O soil respiration, soil temperature and canopy assimilation.

Anal yzer is a porta ble oper ated unit t hat is pow ered by an internal 1 2 V, 2.0

monitoring applications such as

Measurement Principle

The EGM-4 CO2 is a non-dispersive, infrared gas analyzer that features an “Auto-Zero” facility. Using infra-red gas analysis techniques, we can readily determine CO

(Carbon

Dioxide) concentrat ions to within a fe w ppm and instantaneous measurements are pos sible. Gases with di-atom ic m olecules such as CO For CO

one region of strong abs orption is 4.26 m icrons. A source em itting strongly at th is

2 ,

strongl y absorbs p hot ons in t he inf ra-red range.

wavelength is a light bulb. If this is positioned at one end of a tube and at the other en d is placed a sensor that is s ensitive to photons a t 4.26 microns, we have a simple infra-red gas Analyzer. As carbon dioxid e is passed down the sam ple cell, it absorbs some of the infra-red and the sensor reading decreases. The “Auto-Zero” feature, which occurs at regular intervals, allows for f ast warm-up, adaptation to changing ambient conditions and excellent stability of the CO

signal. The action of auto-zeroing minimizes the effects on span (gas

sensitivity) of sample cell contamination, source aging, changes in detector sensitivity and changes in pre-amplifier gain.

The entire optical bench assembly (i.e. sample cell) is filtered and should never require replacement.

To ensure proper operation, the EGM-4 MUST always

be operated in a vertical, upright position.

The EGM-4 can be supplied with t wo different optical benches. One b ench is optimized for measurement of C O bench is optimized f or 0-50,000 ppm and 0-10 0,000 ppm. All instruments are checked and calibrated at the c oncentr ation specif ied a t time of order to ensur e th at the r ead ings ar e < 1% of that value. When an instrument is reset to its default values (i.e. when the system is initialised, see Initialisation on page 43), it returns to this setting.

It is important to note that the information contained in this documentation normally refers to the latest firmware (EPROM) which can change over time. We recommend that all users keep in contact with us from time to time to ensure that they are running the most up to date system firmware.

in the ranges of 0-1,000 ppm up to 0-30,000 ppm. T he other optical

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Getting Familiar With The EGM-4

LCD Display

Custom,

Sensor I/O

RS232

Gas In Port

Gas Out Port

4-20 mA

Access Hole

Getting Familiar With The EGM-4

(2 x 16)

Character

Front Panel

Figure 1 EGM-4 Display (Front Panel)

Connector

tactile keypad

Connectors

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Getting Familiar With The EGM-4

Top of EGM-4

Back Panel of EGM-4 fitted with 12V Lead Acid Battery

Back panel of EGM-4 fitted with 12V NiMH Battery

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Getting Familiar With The EGM-4

Probe Type

PP Systems Sensor

Code Resistor

The EGM-4 is being used as a stand alone IRGA (no external sensors connected)

Not applicable. This is

selection.

STP-1 Soil Temperature Probe

100 KΩ

Not Applicable. Used to be used with older sensors.

56 KΩ

TRP-1/TRP-2 Temperature/PAR Probe

36 KΩ

PAR-1/PAR Sensor

27 KΩ

Not Applicable. Used to be used with older sensors.

20 KΩ

Not Applicable. Used to be used with older sensors.

15 KΩ

Steady State Porometer (PMR-5)

Not applicable. This is

selection.

SRC-1 Soil Respiration Ch amber or CPY-

4 Canopy Assmiliation Chamber

(Closed System operation)

9.1 KΩ

OP-1/OP-2 O2 Sensor

20 KΩ

Not Applicable. Used to be used with older sensors.

5.6 KΩ

CFX-1 Open System Soil Respiration Chamber or CPY-3 Canopy Chamber.

4.3 KΩ

CPY-4 Canopy Assimilation Chamber (Closed System Operation)

9.1 KΩ

Environmental Sensor Inputs (I/O Ports)

The EGM-4 has 2 environmental sensor inputs (I/O) to allow external sensors (i.e. soil respiration chamber, CPY-2/CPY-3/CPY-4 Canopy Assimilation Chambers, TRP-1 Temperature/PAR Pro be, PAR-1 Probe, etc.) to be used sim ultaneously. All sensor inputs lines require 0-1V input. Note, the sensor inputs are displayed in mV (i.e. 0-1,000 mV) instead of Volts.

If one of our environmental sensors is used with the EGM-4, it must be plugged into the instrument prior to turn ing it on. T he EGM-4 automatically detec ts t he sensor c on nected as a result of code resistor s which ar e fitte d to the 15 pi n D C onnector bet ween pins 1 and 6. The code resistors for our environmental sensors are as follows:

determined by keypad

2/CPY-

Note. When the EGM-4 is suppl ied with a PP System s accessory (i.e. SRC -1, CPY-4, etc.), the probe type will be set at the factory based on t he accessory supplied. T herefore, it ma y be necessary to chan ge the pr obe t ype if required . The pro be type c an be chan ged from the

2SET m enu on page 30. if required. See Analog Output on page 13 for analog out put pin-

outs and location for code resistor placement (Pin 1).

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Getting Familiar With The EGM-4

DB15 I/O

Connector

Description

Code Resistor (connect to pin 6)

PAR

RH 4 Aux. Analog Input

Temp

+5V

Alarm 1 (Buffered)

Digital Ground

RS232 Output

Data Request /CO2 Control

RS232 Input

+12V

Aux. Digital I/O

CO2 Analog Out

Analog Ground

9 PIN D Socket on

EGM-4

9 Pin D Socket on PC

Pin 2

Pin 5

Analog Output

The EGM-4 has two 15 pin I/O c onnectors with a 0-5V analog ou tput. The default output is set at 0-5V. However, this can be changed by the us er (if required) to an y value in between (i.e. 0-1V, 0-2V, 0-3V, 0-4V). (See 7VOUT on page 34). The pin-outs for the two I/O connectors are as follows:

Current Output

If required, current output (4-20 mA) is available and can be acc essed through the top of the EGM-4. Inside the EGM-4, there is a 2 pin connector labelled CN7 on the PC075-1 cir cuit board. The EGM-4 contai ns a 4-20 mA current transm itter that is powered from an internal 12V supply. To utilize the curr ent output, simply connect the Iout pins dir ectly to a 4-20 mA meter or digitizer. No power suppl y or other c onnect io ns ar e requir ed to g et a 4-20 mA output from the EGM-4. Appl ying voltage to th e Iout pins higher th an 12 V will d amage the interna l circuitry.

RS232 Port

The EGM-4 has one 9 pin RS232 connector used for transferring stored data to a PC or laptop computer. To trans fer s tor ed data f r om the EGM-4 to an external PC, connect the dat a transfer cable (suppl ied by PP Systems) between th e RS232 connector on the EG M-4 and the 9 pin serial connec tor on t he PC. Da ta transf er sof tware (suppl ied b y PP System s) steps you through the data transf er process. See Data Du mp on page 37 for more inf ormation on data transfer. If required, a data transf er c able can ea sily be m ade up b y the use r. See table below:

Soda Lime Absorber Column

The absorber colum n is labelled “Soda Lim e” on the r ear panel. It contains a CO2 scrubbing desiccant known as Soda Lim e. When air passes through this colum n, it removes all of the

from the air stream. The “Auto-Zero” fac ility built into the EGM-4 periodica lly switches

the flow of gas from the Analyzer through this column to check the Analyzer zero. This routine ensures long term stability and accuracy of the CO

Analyzer. It automatically

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Getting Familiar With The EGM-4

corrects for such things as sample cell contamination, sour ce aging, detector sensitivity and changes in electronics.

Soda Lime

Soda lime is used to remove CO2 from air entering the EGM-4. It is supplied as selfindicating granules (1-2.5mm) that turn fr om green to brown as it becomes exhausted. T he contents of the absorber column should be replaced when it is 2/3rds exhausted (brown). Soda Lime cannot be rege nerated and should be dis carded when exhausted. For ac curate measurements and cali bration, it is absol utely critical that th e EGM-4 absorb er column is not exhausted. If the soda lim e is becoming exhausted, it w ill cause the ZERO to be perform ed on non-ZERO air causing an error in the calibration.

When exhausted, the So da Lime Cap shou ld be removed along with the f oam filter pad ( with the EGM-4 facing upwards ) and the contents discarded. W hen replacing the soda lime, we recommend using a funnel to ensure that the desiccant fills the absorber column. Leave approximately 1” from the end of the column to allow the foam pad and cap to be refitted.

! CAUTION !

WASH YOUR HANDS AFTER HANDLING SO DA LIME

Keypad

The custom, tactile keypad consists of 12 keys. There are ten keys that are labelled 0-9. Also, there are a few keys that have a dditional functio ns. The Y/R (Yes/Record) k ey is used to accept settings and to record measurements. In addition, the Y/R key is pressed to advance from one disp lay to the next. T he N key is n ormally used to return to t h e M ain M enu from Measurem ent Mode, reject setti ngs or to step back through the menus. T he 8/X k ey is used to toggle from one display to another in Measurement Mode.

LCD Display

The EGM-4 features a 2x16 character, backlit LCD display.

Gas Ports

There are two barb fitt ings locate d on the top of the EGM-4. Each bar b fitting is designed for use with 1/8” (.125”) ID tubing. O ne barb f itting is labelled “G as In” an d the ot her “Gas Out”. The sampling line should b e fitted to the “Gas In” port using 1/8” tubing. The “G as Out” line should be left open to atmosphere to allow the sample air to exhaust without restriction. Note, for closed system measurements with our SRC-1 Soil Respiration Chamber or CPY-2 Canopy Asssimilaton Cham ber, one gas line is connected to the “Gas In” por t and the other to the “Gas Out” port.

Battery

The EGM-4 can be powered by an internal 12V 2.0 Ah lead acid rechargeable battery providing up to 4 h ours c ontinu ous use or a 12V N iMH rechar geable b atter y prov idin g up to 8 hours continuous use.

Powering The EGM-4 With Internal 12V NiMH Battery

There are two ways to power the EGM-4 :-

1. Using the internal 12V NiMH battery:

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Getting Familiar With The EGM-4

LED

Mode

Orange

Battery not connected

Orange

Battery initialization & anal ysis

Red

Fast charge

Green with intermittent orange flash

Top-off charge

Green

Trickle charge

Alternating red-green

Error

Input

100-240 V ~ 50-60 Hz

A. Set the slide switch on the rear panel of the EGM-4 to the 'BATTERY'

position.

B. Switch the instrument on using the 'POWER' toggle switch.

Note, the internal battery CANNOT be used to power the EGM-4 while it is being

charged, but the external power supply can be used simultaneously instead.

2. Using the external power supply A. Set the slide switch on the rear panel of the EGM-4 to the 'CHARGE' position.

B. Plug the EGM-4 External Power Supply into the '-ve/+ve' socket. C. Switch the instrument on using the 'POWER' toggle switch.

CHARGING THE INTERNAL 12V NiMH BATTERY

1. Set the slide switch on the rear panel of the EGM-4 to the 'CHARGE' position.

2. Plug the EGM-4 NiMH Battery Charger into the 'CHARGE SKT'. T o do this, line up the three socket pins with the plug, and screw on the plug sleeve (do not overtighten).

Charge Cycle and LED Indications for 12V NiMH Battery Charger

Check to make sure that the “charge indicator light" (red LED) on the charger is a steady state red after connection. If the LED does not come on, or it fluctuates , then there may be a bad connection.

WARNING

THE EGM-4 IS FITTED WITH A SLIDE SWITCH (CHARGE   BATTERY).

DO NOT OPERATE THE SLIDE SWITCH WHEN THE EGM-4 IS

CONNECTED TO ANY EXTERNAL POWER SUPPLY OR BATTERY

CHARGER.

Charge Socket

The charge socket is labelled “12V DC” on the rear panel of the EGM-4. The AC Adapter/charger sup plied b y PP S ystems plugs into t his sock et to charg e the inter nal 12 V 2.0 Ah lead acid battery.

Power Supply/Charger

All systems are suppl ied complete with an A C Adapter/Charger desi gned specificall y for use with the EGM-4 for charging the internal 12 V 2.0 Ah lead acid battery and for continuous operation in the lab. This unit has the following technical specification:

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Getting Familiar With The EGM-4

Output

15 V @ 2.7 A

Power Indicator

Green LED

Dimensions

10.5 cm x 6.5 cm x 4.5 cm

Weight

0.3 kg

!!! WARNING !!!

USE OF POWER SUPPLIES AND BATTERY CHARGERS OTHER THAN

THOSE SUPPLIED BY PP SYSTEMS FOR THE EGM-4 WILL INVALIDATE

THE WARRANTY.

Please note. EGM-4’s can also be powered by an internal, rechargeab le 12V NiMH batter y for extended operati on in t h e f ield. For more information on th is opt io n, refer to Poweri ng T he

EGM-4 With Internal 12V NiMH Battery on page 14.

Power Switch

To power up the EGM-4, the On/Off Switch should be toggled to the “On” position. To turn the instrument off, the switch should be toggled to the “Off” position.

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Operation

EGML

PMR

Refers to an EGM-4 with a measurement range up to 30,000

Refers to PMR-5 Steady State Poromter.

0456

Refers to the serial number of the EGM-4

V1.30

Refers to the firmware (EPROM).

C2000

Corresponds to the last c alibration gas concentr ation. After DEFAULT, it is th e original range specified by the end user.

1V=2000

Range of the voltage signal corresponding to the CO2 concentration.

R150

Number of records stored in memory.

PP SYSTEMS C2002

C2000 1V=2000

C2000 5V=2000

Operation

The EGM-4 is a menu driven instrum ent. Note. If any external sensors/p robes are to be used with the EGM-4, they MUST be electrically connected to one (or both) of the I/O ports prior to turning the instrument on. When the instrument is f ir st powered up, it wi ll go

through its normal warm-up period that takes approximately 5 minutes. Immediately after powering up the system, the following is displayed:

Whereas:

EGML 0456 V1.30

EGMH

During warm-up, there is a delay of approximately 45 seconds to allo w for calibration of the electronics and then the instrument proceeds to warm-up until the Analyzer temperature reaches 50 ˚C. A final Zero check is then performed before proceeding to the Main Menu.

Also during warm-up, several system checks are performed. The “Checksum” message is set to a factory default value of 123456. If this is incor rect as whe n a new version of firmware is first installed, a “CHECK SUM ERROR SEE MANUAL” message is displayed. If this occurs, simply press any k ey to proceed to the M ain Menu. From the Main Me nu, press k ey 0 to reinitialise the system (See Initialisation on page 43).

The next display will be d ependent on whether or not any extern al sensors are being used with the EGM-4.

If the EGM-4 is being used on its own, the following will be displayed:

Where:

ppm.

Refers to an EGM-4 with a measurement range of 50,000 or 99,999 ppm.

mV INPUTS R150

If the EGM-4 is being use d with an external sensor (i.e. SRC-1 Soil Res piration Chamber), the following will be displayed:

EGM-4 Operator's Manual – Version 4.19

PROBETYPE 8 R150

- 17 -

Page 18

Operation

C2000

Corresponds to the las t calibration gas concentr ation. After DEFAULT , it is the original range sp ec if ied b y the end user.

5V=2000

Range of the voltage signal corresponding to the CO2 concentration.

PROBETYPE 8

Refers to the probe/sensor connected to the EGM-4. For a list of probe types, see Environmental Sensor Inputs (I/O Ports) on page 12.

R150

Number of records stored in memory.

C2000

Corresponds to the las t calibration gas conc entration. After DEF AULT, it is the original range specified by the end user.

5V=2000

Range of the voltage signal corresponding to the CO2 concentration.

POROMETER

Refers to the PMR-5.

R150

Number of records stored in memory.

Key

To:

Z/0

Perform a manual Zero.

Y/R

Record a measurement and place it in memory.

8/X

Changes to a different display (See section 1REC).

Return to the Main Menu.

1REC 2SET 3CAL

C2000 5V=2000

Where:

If the EGM-4 is being used as a porometer (i.e. PMR-5), the following will be disp l a yed:

Where:

POROMETER R150

After all system checks have been perf ormed and the s ystem achieves warm-up, the EGM-4 Main Menu is displayed as follows:

Note. If the instrument was just powered up, the display will show “WARM UP DELAY TEMPERATURE = XX ” until the instr ument achieves its warm up temperature of 50 ˚C prior to the Main Menu.

While in Measurement Mode, the following key presses can be performed:

Refer to the following sections for more information on menus and displays.

4DMP 5CLR 6CLK

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Page 19

Operation

Press

Key

Go Into Measurement Mode. See 1REC on page 19.

Change system settings (i.e. zero type and time interval, recording type, alarm settings, etc.). See 2SET on page 30.

To calibrate the Analyzer. See 3CAL on page 35.

To dump stored data to a PC or to v iew data on the LCD display. See 4DMP on page 36.

Clear system memory. See 5CLR on page 41.

Set/check the system clock (date and time). See 6CLK on page 42.

If the EGM-4 is used as a:

Then The

set to:

Stand Alone CO2 Analyzer (including optional humidity sensor page 20.

Environmental Monitor (With one of our Environmental Sensors such as %RH,

Environmental Monitor

(Probe Types 1-6 and 10) on page 22.

1-5

Steady State Porom eter. See Steady State Porom eter (Probe

Type 7) on page 23.

Closed System Soil Respiration

Soil Respiration (Probe Type 8) on page 24.

O2 probe

RH and Temperature

Open System Measurement

Open System Soil Respiration (Probe Type 11) on page 27.

Closed System operation with the CPY-4. See Closed S ystem

Soil Respiration (Probe Type 8) on page 24.

1REC 2SET 3CAL

Main Menu

There are 6 options available to the user when the Main Menu is displayed as follows:

Where:

Each option is discussed in further detail below.

4DMP 5CLR 6CLK

1REC

To begin recording, pr ess key 1. Please note, the EGM-4 dis play is dependent upo n which probe type is connected to it. The following table illustrates the Probe Types:

Probe Type is

is fitted). See S tand Alone CO2 A nalyzer (Probe Type 0) on

temperature, PAR, O2, etc.). See

(i.e. SRC-1 Soil Respiration Chamber). See Closed System

(i.e. CFX-1 Soil Respiration Chamber, CPY-3 Chamber). See

Important Note. Most instruments are supplied with the probe t ype alread y set if a sens or is supplied with the EGM-4. If an exis ting EGM-4 user purchases an environmental sens or f rom us, it may be necessary to set the probe type (see 1EGM on page 30).

In the followng sections, some displays will vary slightly to what is discussed depending on firmware and sensors co n n ected to the EGM-4.

EGM-4 Operator's Manual – Version 4.19

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Page 20

Operation

CO2 concentration (ppm)

Humidity (mb). Only if optional %RH/Temp sensor is present.

Absolute pressure in sample cell (mb).

Refers to probe type. See 1REC on page 19.

C 545

C 545 H11.2

Display 1A (without optional %RH

Display 1B (with optional humidit y

Stand Alone CO2 Analyzer (Probe Type 0)

To begin recording, press key 1. Immediately after pressing key 1, the instrument will automatically perform a zero check. Once completed and assuming no problems with the zero, the instrument will proceed to “Measurement Mode” where the CO additional values if opt ional humidity sensor is present) being m easured by the instrum ent is displayed as follows:

Sensor)

A1011 P00

Where:

To return to the Main Menu while in Measurement Mode, simply press the N key. Note. If the instrument was just powered up, the display will show “WARM UP DELAY

TEMPERATURE = XX ” until the instrum ent achieves its war m up temperature of 50 to entering into Measurement Mode.

Additional information (i.e. external sensors, etc.) may be viewed on the LCD display if required. While in Measurement Mode with the CO

concentration displayed, subsequent

presses of the 8 key will show additional displays as follows:

value (plus

C prior

EGM-4 Operator's Manual – Version 4.19

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Page 21

Operation

Display 1A

Display1B (if optional humidity sensor is fitted)

Display 2

REC

Record Number

PLOT

Plot Number

19-12

Date (19th day of December)

13:05

Time (1:05 PM)

Signal (mV) from sensor connected to Pin 1 on the 15 pin D Connector.

Signal (mV) from sensor connected to Pin 2 on the 15 pin D Connector.

xxxx

Signal (mV) from sensor connected

on the 15 pin D Connector.

the letter C is not displayed.

Signal (mV) from sensor connected to Pin 4 on the 15 pin D Connector.

Signal (mV) from sensor connected to Pin 5 on the 15 pin D Connector.

Display 2

REC

Record Number

PLOT

Plot Number

19-12

Date (19th day of December)

13:05

Time (1:05 PM)

Signal (mV) from sensor connected to Pin 1 on the 15 pin D Connector.

Signal (mV) from sensor connected to Pin 2 on the 15 pin D Connector.

xxxx

Signal (mV) from sensor connected

letter C is not displayed.

Signal (mV) from sensor connected to Pin 4 on the 15 pin D Connector.

Signal (mV) from sensor connected to Pin 5 on the 15 pin D Connector.

C 545

C 545 H11.2

Axxxx Bxxxx xxxx

REC 0066 PLOT 10

Axxxx Bxxxx xxxx

REC 0066 PLOT 10

Measurement Mode Display Structure

Press Key 8 to display the following:

Where:

Press Key 8 to display the following:

Where:

A1011 P00

19-12 13:05

Dxxxx Exxxx

Display 3

Where:

A1011 P00

Press Key 8 to display the following:

19-12 13:05

Press Key 8 to display the following:

Dxxxx Exxxx

Display 3

to Pin 3 Note. Due to limits on the display,

See Environmental Sens or Input s on page 12.

Press key 8 to return to Display 1A in

Measurement Mode.

The record number r esets each tim e the instrument starts or when the m emory is c leared. It counts up to 9999 a nd then resets automaticall y to 1. The internal EGM-4 m emory allows data storage of up to 1,000 records. Please note, when the memory is full, it overwrites

the oldest records.

EGM-4 Operator's Manual – Version 4.19

to Pin 3 on the 15 pin D Connector. Note. Due to limits on the display, the

See Environmental Sens or Input s on page 12.

Press key 8 to return to Display 1B in

Measurement Mode.

- 21 -

Page 22

Operation

CO2 concentration (ppm)

Humidity (mb). Only if optional humidity sensor is present.

Air Temperature ( oC)

PAR (µmol m-2 s-1)

Relative Humidity (%). If the optional humidity sensor is fitted to the EGM-4, press key 8/X to see the humidity displayed in mb.

REC

Record Number (up to 9999).

PLOT

Plot Number (up to 99)

03-04

Date (3rd day of April)

12:40

Time (12:40 PM)

C 365 T24.3 REC 0001 PLOT 00 03-04 12:40

Changing Plot Number

If the plot number needs to be chang ed, press key N when Display 2 above is shown and enter the plot number desired. Next, press the Y key to continue. To return to Displa y 1 press key 8/X twice. Only the plot number can be changed at this point and the record number automatically resets to 1 when the plot number changes.

Environmental Monitor (Probe Types 1-6 and 10)

Immediately after pressing key 1, the instrument will automatically perform a zero check. Once completed and assuming no problems with the zero, the instrument will proceed to “Measurement Mode” wher e the CO sensor values are displayed as follows (Display 1):

Where:

v alue (plus optional %RH /Temp sensor is present) and

Q 1200 RH 65.3

Note. If the instrument was just powered up, the display will show “WARM UP DELAY TEMPERATUR E = XX” until the instrument achieves its warm up temperature of 50 ˚C prior to entering into Measurement Mode.

Press key 8/X to view record number, plot number, date and time (Display 2):

Where:

The record number r esets each tim e the instrument starts or when the m emory is c leared. It counts up to 9999 a nd then resets automaticall y to 1. The internal EGM-4 m emory allows data storage of up to 1,250 records. Please note, when the memory is full, it overwrites

the oldest records.

The Plot Number c an b e ch anged as explained in the s ec tion Ch ang in g Pl ot N umber on pa ge

22. Additional inf ormation ma y also be viewed on the LCD displa y. While in Measurem ent Mode

with the CO

concentration and se ns or dat a d isplayed, subsequent pr es ses of the 8/X key will

show additional displays as outlined in Measurement Mode Display Structure on page 21.

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Page 23

Operation

REC

Record Number (up to 9999).

PLOT

Plot Number (up to 99)

03-04

Date (3rd day of April)

12:40

Time (12:40 PM)

Inlet Relative Humidity (%RH)

Outlet Relative Humidity (%RH)

Porometer Temperature (˚C)

PAR (µmol m-2 s-1)

Flow Rate (ml/min)

Stomatal Conductance (mmol (H

O) m

² s-¹ )

REC 0001 PLOT 00

KEY 2 = HUMIDITY

I 22.3 O28.4 T22

PP Systems Environmental Sensor Conversions:

The following conversions need t o be m ade to determ ine actu al m easur em ents of PAR, %RH and temperature when using PP Systems’ environmental sensors.

PAR Sensor mV x 3 = PAR Level (µmol m

-2 s-1

)

%RH Sensor mV / 10 = %RH Temperature mV / 20 = Temperature (˚C)

To return to the Main Menu while in Measurement Mode, simply press the N key.

Steady State Porometer (Probe Type 7)

Immediately after press ing key 1, the instrument will displ ay the following message to allow the sensors to time for alignment (Display 1):

After approximately 3 seconds, the following is displayed to allow entry of record and plot number if required (Display 2):

Where:

SENSOR BALANCE

03-04 12:40

Note. If the plot number needs to be chan ged, press k ey N when Display 2 above is sho wn and enter the plot num ber desired. Next, press the Y k ey to continue. T o return to D ispla y 1 press key 8/X twice. Only the plot number can be changed at this point and the record number automatically resets to 1 when the plot number changes.

To proceed to the Measurement Display, press the 8/X key (Display 3):

Q1645 F245 G 0234

Where:

The stomatal conductance calculation uses an exact determination of the energy balance. To return to the Main Menu while in Measurement Mode, simply press the N key.

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Page 24

Operation

Description

SRC-1

CPY-4

mm into soil

CPY-4

mm into soil

1V:

Volume of the system up to 999,999 (ml)

1171

2427

2344

Area exposed up to 9999 (ml or cm3)

167

SOIL RESP.DATA

1V: 1171 2A: 78

DATA FITTING

Closed System Soil Respiration (Probe Type 8)

Before performing closed s ystem measurements with the SRC-1 Soil Respiration Chamber (or CPY-2/CPY-4 Canopy Assimilation C hambers), see the section o n Condensation Ris k on page 6 at the beginning of this manual to ensure that you do not encounter any prob lems related to water in the analyzer.

Use of our PAR Sensor with SRC-1 Soil Respiration Chamber

If you have one of our PAR Sensors and you want to use it along with the SRC-1 Soil Respiration Chamber, you need to follow these steps.

1. Connect both the SRC-1 and PAR sensor to the EGM-4 and power it up.

2. From the Main Menu, press 2SET.

3. Press 1EGM and then the N key 3 times.

4. Enter 08 for Probe Type and say Yes to accept.

5. Press key N to return to the main menu.

Immediately after pres sing key 1, the instrum ent will perform zero checks ( and may display the “Warm Up Delay” message if the EGM-4 was just powered up) prior to displaying the following message (Display 1):

The assimilation (resp iration/photosynth esis) rate is calculate d by plotting the rat e of change in the chamber CO

concentr ation. The user has the option of saving the full data used i n

fitting the soil respira t ion r at e c urve or the final res u lts. If you want to save t he f ul l s et of data, press key 1. Note, data is collected every 4.8 seconds. If 1 is selected (ALL), the internal memory will allow you to s tore approx imately 80 m inutes of continuous data. S ince there are typically several minutes in between meas urements, you could expect to s tore approxim ately ½ days work. If 2 is selected, only the final results will be saved and recorded.

Next, choose linear or quadratic fitting for the soil respiration data (Display 2). If you are unsure which option to choos e, we recommend option 2QUAD (quadratic f itting). For more information on this, please refer to the SRC-1, CPY-2 and CPY-4 technical documentation.

Please note. If a quadratic fit is selected an d the ppm change is less than 0.2ppm /second, a linear fit is used. The system always starts up with the SRC-1 default values. See table below for default val ues f or SRC -1 and CPY-4. If us ing t he CP Y-4 or no n-s tand ar d c hambers with the EGM-4, press k e y 1 to change the s ystem volume, key 2 to change the area expos ed for the proper values (Display 3):

Where:

RECORD 1ALL 2END

1LINEAR 2 QUAD.?

3V/A*100 1491

With ring 5

EGM-4 Operator's Manual – Version 4.19

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With ring 10

Page 25

Operation

3V/A*100

Volume/Area. This is

maximum.

1DT:

Time for which the c hange in the chamber CO2 concentr ation is monitored respectively.

2DC:

The maximum change allo wed in CO2 concentr ation from time zero at which point the final measurement is made (ppm).

3TEMP:

The approximate air temperature (°C).

4SRDIV:2

Only available from firmware version 1.51 and above. Prior to V. 1.51, a

number in soil

SRDIV

Corresponding 4 digits to SR

Max. SR reading

Min. SR

999.9

0.1

2 (default)

100

99.9

0.01

1000

9.999

0.001

PLOT

Plot Number (up to 99)

1DT:120 2DC: 50

PLOT NO = 0 Y OR NEW VALUE

CHAMBER FLUSHING

automatically updated whe n there is a change to 1 (Volume)

Automatically updated/calculated based

on values entered abovee or 2 (Area). Also, if this value is changed directly, 1 (Volume) and 2 (Area) are set to

Important Note. If using the SRC-1 or CPY-4 with collars you must remember t o acc ount for the extra volume under 1V for proper calculation of rates.

Press key Y to ad vance to the next dis pla y. Press k ey 1 to change t he tim e, ke y 2 to cha nge the CO

concentration or key 3 to change the approximate air temperature (Display 4):

3TEMP 25. 4SRDIV:2

Where:

(seconds). The minimum and maximum values are 30 and 999 seconds

divisor of 100 was used to convert the four digit SR respiration units in g/m2/hr limiting the max imum recording r ate to 99.99 . V.

1.51 allows for a selectabl e SR divisor hat c an be set to 10, 100 or 1000 f or maximum reported SR of 999.9. The default SRDIV value is 2.

Setting

Divisor to convert

Press key Y to advance to the next display (Display 5):

Where:

Note. If the plot number n eeds to be changed, sim ply enter the new value ( leading zeroes required for values less th an 10, i.e. 05 for plot number 5) and press key Y when Display 5 above is shown. To return to Displ ay 1 press key 8/X twice. Only the plot number can be changed at this point and the record num ber automaticall y resets to 1 when the plot number changes.

The next display is as follows (Display 6):

HOLD IN AIR 03

Reading

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Page 26

Operation

C 395

Current measured CO2 concentration (ppm)

H14.7

Humidity concentration if optional %RH/Temp sensor is present (mb)

T22

Soil Temperature if optional STP-1 probe is present (˚C)

A02.11

CO2 exchange (Assimilation) rate (g (CO2) m2 Hour). The maximum rate that can be recorded is 99.99 g (CO2) m2 Hour.

Q0000

PAR (µmol m-2 s-1)

110

The elapsed time of measurement (seconds). At the conclusion of measurement, END will be displayed.

EQUILIBRATION

C 395 H14.7 T22

NON-LINEAR FIT

PLACE ON SOIL

C 395 H14.7 T22

RECORD Y/N

At this stage, the SRC-1 chamber should be held in the air to allow it to flush out prior to placing it on the soil. T he num ber in the bot tom r ight (03 in th is case) is a count from 0-15 in

1.6 second increments. When completed, the following is displayed (Display 7):

PRESS Y TO START

After placing the SRC-1 ch am ber on the s oil, press the Y ke y. The following will be disp layed (Display 8):

PLEASE WAIT 03

After approximately 5 seco nds, the measurement will comm ence. Before final calculation of soil respiration rate (g (CO

) m2 Hour) can be achieved , the EGM-4 m us t have accum ulated 4

data sets. The measurement display is as follows (Display 9):

A02.11 Q0000 110

Where:

At the conclusion of measurement, the following is displayed:

A02.11 Q0000 END

At completion of measurement (with END displayed), press any key to continue. You are now given the option to save the record.

Press the Y key to save the record. Press the N key if you do not want to save the record.

Please Note. If the DC or DT exceeds the set values, the following message is displayed:

This message is displayed with the quadratic fit if the C term in the quadratic fitting expression (Y = a + bx + cx

) is greater than 0.1 x b.

EGM-4 Operator's Manual – Version 4.19

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Page 27

Operation

CO2 concentration (ppm)

Humidity (mb). Only if optional humidity sensor is present.

Air Temperature (oC). Only if optional %RH/Temp sensor is present.

O2 concentration (%)

Relative Humidity (%RH)

REMOVE FROM SOIL

C 365 T24.3

CPY 1:5L 2:20L 3:100L

RECORD Y/N

At this stage, the user is still given the opportunit y to save the meas urement even though t he DC an DT settings were exceeded.

If you still want to save the m easur em ent, pr ess k e y Y. If not, press key N. After making your selection, the following is displayed:

THEN PRESS Y KEY

The measurement proc es s begins as des c ribed ab ov e. Note. If a ZERO is r equir ed, it will be performed in between m easurements. At any time, a key press of N will return you to the display that shows V olume, Area, etc. (Disp lay 3 above) and the s ettings can be changed if required. A subsequent press of the N key will return you to the Main Menu.

To return to the Main Menu while in Measurement Mode, simply press the N key. For more information on the theory and calculation of soil respiration/canopy assimilation,

please refer to the SRC-1 Soil Respiration Chamber or CPY-4 technical documentation.

Oxygen (Probe Type 9)

and O2 value (plus Humidity and Tem perature if sensor

is present) and sensor values are displayed as follows (Display 1):

O% 20.9 RH 65.3

Where:

Open System Soil Respiration (Probe Type 11)

Before starting any meas urements with the CFX-1 or CPY-3 chambers, s ee the section on

Condensation Risk on page 6 t o ensure that you do not enc ounter any problems related to

water in the analyzer. Immediately after pressing key 1, the instrument will display the following message

(Display 1):

4:CFX

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Page 28

Operation

1:5L

Select 1 if operating our CPY-3 chamber with 5 Litre/min flow.

2:20L

Select 2 if operating our CPY-3 chamber with 20 Litre/min flow.

3:100L

Select 3 if operating our CPY-3 chamber with 100 Litre/min flow.

CFX

Select 4 if operating our CFX-1 Soil Respiration Chamber

REC

Record Number (up to 9999).

PLOT

Plot Number (up to 99)

03-04

Date (3rd day of April)

12:40

Time (12:40 PM)

Reference CO2 concentration (ppm)

Difference between Reference and Analysis gas (ppm)

Temperature of the CFX-1 or CPY-3 Chamber (˚C)

CO2 exchange (Assimilation rate) (µmol m2 s-1).

Flow Rate (ml/min)

R/A

Indicates if Reference or Analysis is being sampled

REC 0001 PLOT 00

R00345 D+0020 T22

Where:

Select the appropriate cha mber (CPY-3 or CFX-1). If one of the CP Y-3 c hambers is selected, it is necessary to ent er or t o c heck that the area covered by the cham ber is c orr ec t. Note , th e entry is in cm

up to 9999 or appr oximately 1 m2. If 9999 is entered whe n the true area is

smaller, the calculated flux will be the chamber flux.

After performing a Zero, the next display will be as follows (Display 2):

03-04 12:40

Where:

Note. If the plot number needs to be chan ged, press k ey N when Display 2 above is sho wn and enter the plot number desired. Next, press the Y k e y to continue. T o return to Dis play 1, press key 8/X twice. Only the plot number can be changed at this point and the record number automatically resets to 1 when the plot number changes.

To proceed to the first measurement display, press the 8/X key (Display 3):

A06.15 F0300 R

Where:

If you press the 8/X key, the standard EGM-4 data is displayed (i.e. CO

, H2O, etc.).

EGM-4 Operator's Manual – Version 4.19

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Page 29

Operation

With the CPY-3 only, the atmospheric pressure Annnn is replaced by the PAR reading (Qnnnn).

If the EGM-4 is fitted with the optional humidity/temperature sensor, then these measured parameters are also displayed.

Use the 8/X key to scroll round Displays 2,3 and St and ard To save the measured data at any time, press key Y. To return to the Main Menu simply press the N key when either Display 2 or 3 is shown.

System Equilibrium

The EGM-4 is an absolut e analyzer. In order to work with open-type chambers, an internal solenoid (built into the cha mber) switches ever y 30 seconds to select either t he reference or analysis sample gas stream for measurement. Therefore, a minimum of 45 seconds must elapse before valid data is ava ilable. However, this is not the time taken to get to equilibrium which depends on the chamber volume and the flow rate.

For example, with the CFX-1 the effective volume between the Reference and Analysis sampling points is approximately 2.2 litres :

System Response Time (minutes) = Chamber Volume (2.2litres) / Flow Rate (litres/minute) So at a Flow Rate of 1litre/minute, System Response Time = 2.2 minutes Assuming the system is perfectly mixed then there is an exponential approach to equilibrium:

63% of final value achieved in 1 System Response Time 86% of final value achieved in 2 System Response Times 95% of final value achieved in 3 System Response Times 98% of final value achieved in 4 System Response Times

Calculation Of Fluxes For CFX And CPY Chambers

Both the CFX-1 and CPY-3 c hambers use Honeywell m ass flowmeters that are calibrat ed at STP which is 0

for H

Convert the flow (V) meas ured in ml m in of (A) cm

= ( V x 10000 ) / ( A x 22.414 x 1000 x 60) = (V / A ) x 7.436 x 10 With a CO ∆C x (V / A ) x 7.436 x 10 and with an H ∆H x (V / A ) x 7.436 x 10 For CO

For H

O, to convert to g H2O m2 h-1 , multiply by 64.87.

C and 1013mb. R esults are gi ven in µmol m

-1

to mol m-2 s

differential between the inlet and out let of ∆C ppm, the CO2 flux is:

O differential between the inlet and outlet of ∆H mb, the H2O flux is:

to convert to g CO2 m2 h

-1

(Molar Volume at STP is 22.414 l.)

-1

at STP thro ugh the cham ber with an e xposed area

-3

µmol m-2 s

-3

mmol m-2 s-1 .

-1

, multiply by 0.1584.

-2 s-1

for CO2 and in m m ol m

EGM-4 Operator's Manual – Version 4.19

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-2 s-1

-3

Page 30

Operation

:MV

EGM-4 set to analyzer only with auxiliary inputs displayed in mv. Probe type should be set to 0 in this case.

Probe Type (See Probe Types table below).

Press Y if the settings are correct.

Press N to change the Probe Type

Probe Type

PP Systems Sensor

The EGM-4 is being us ed as a s tand a lone I RGA (n o ex ternal s ensors connected)

STP-1 Soil Temperature Probe

Not Applicable. Used to be used with older sensors.

TRP-1/TRP-2 Temperature/PAR Probe

PAR-1/PAR Sensor

Not Applicable. Used to be used with older sensors.

Steady State Porometer (PMR-5)

SRC-1 Soil Respiration Chamber or CPY-2/CPY-4 Canopy Assmiliation Chamber (Closed System operation)

OP-1/OP-2 O2 Sensor

Not Applicable. Used to be used with older sensors.

1EGM2Z: 3PMP 4AV 5RECD 6ALM 7VOUT

:MV 0:PROBE Y=OK N=CHANGE

2SET

Press key 2 from the Main Menu if you need to:

• Select/change probe types us ed with the EGM-4 (1EGM on page 30).

• Select/change the EGM-4 Zero (2Z on page 31).

• Enable/disable sampling pump (3PMP on page 32).

• Determines within which range of outputs the average is to be taken (4AV on pag e 32).

• Change the instrument recording feature, automatic vs. manual (5RECD on page 33).

• To set the high and low alarm (6ALM on page 33).

• To change the analog voltage output, 1-5V, (7VOUT on page 34).

1EGM

Press 1EGM to set the EGM-4 displays accord ing to i nten ded app lic ati on.

Where:

The EGM-4 is quite versatile and can be used as a stand alone gas analyzer, part of an environmental m onitoring system when used with any of our available sensors (i.e. TRP-2, SRC-1 Soil Respiration Cham ber, CPY-4 Canop y Assim ilation Chamber , etc.) or as a s teady state porometer.

To change the probe type from the current setting:

1. Press key N 3 times until ?? appears next to PROBE.

2. Enter the probe type (use leading 0’s for single digit probe types).

3. Press key Y to save.

4. Press key N to return to Main Menu.

Probe Types

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Operation

CFX-1 Open System Soil Respiration Chamber or CPY-3 Canopy Chamber.

CPY-4 Canopy Assimilation Chamber (Closed System Operation)

Auto

This is the recomm ended ZERO type. The EG M-4 performs a Z ero on start up,

minutes. This is the default mode on startup.

Manual

If selected, the EG M-4 performs a Zero on start up, then again aft er 2 minutes,

40 minutes, one will be performed automatically.

EXT

A ZERO can be initiated by pulling DATA/ZERO REQ (Pin 10) line LOW. If no ZERO occurs after 40 minutes, o ne will be performed automatically.

ZEROTYPE *:AUTO

Probe Setting Override

Some users may want to use the EGM-4 as a stand alone IRGA even with a sensor connected. This option is available under 1EGM:

Press 1EGM. The Probe type should be set to the probe type connected to the EGM-4.

1. Press key N once until * appears next to :MV.

2. There should be a blank (no value) next to PROBE.

3. Press key Y to save.

4. Press key N to return to Main Menu.

If you now press k ey 1REC from the M ain Menu, you will e nter into the meas urement mode and the EGM-4 will act as a stand alone IRGA (S ee Stand Alo ne CO2 Analyzer (Probe T ype

0) on page 20.

Press 2ZERO to change the zero type and the time interval for performing zeros.

Changing the Zero Type

Press key 2 (2ZERO) and then key 1 to change the zero type used by the EGM-4. At present, there are 3 types of zeros that can be performed:

then again after 2 m inutes, then again af ter 4 m ore minutes, t hen after 8 minutes and finally after 16 minutes up to a maximum interval set by the ZEROTIME. ZEROTIME by default at start up is 20 minutes but it can be set from 1 to 40

then again after 4 mor e m inutes , the n af ter 8 minutes and finally after 16 minutes. After that, the user is r esponsible for performing Z EROS by pressing the 0 key while in Measurement Mod e. Note, if the user fails to perform a ZERO after

(Connect to Ground Pin 8) Hold f or 3 sec onds a nd t he n br eak gr ound connection.

An asterisk (*) in dicates which Z ERO type is se lected. By def ault, the ZERO T YPE is set to AUTO which is what we recommend.

To change the ZERO T YPE, press key 1 for AUTO, key 2 for MANUAL or key 3 for EXT . Immediately after press ing the key, the asterisk (*) will be displayed next to your selec tion. This will be the ZER O TYPE that will be used by the EGM-4 until changed ag ain. Press key Y to return to the 2SET menu.

2:MANUAL 3:EXT

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Operation

ZEROTIME = 40

SAMPLE PUMP ON

STATIC SAMPLING

Changing the Zero Time

Press key 1 (1ZERO) and then key 2 to change the Auto-Zero time.

Zero time is the interva l between Zeros in minutes wh en ZERO TYPE is set to Auto. If the displayed time is c orrect, simply press the Y key. If you want to change the ZERO TIME, press key N and enter a value up to a maximum of 40. Note, for values less than 10, leading zeros are required (i.e. 05 for 5 minutes). T he new value will be update d on the display. To accept, press the Y key.

Y=OK N=NEW VAL

3PMP

Press 3PMP to enable/disable the i nternal sampling pump. B y default, the sample pum p is on.

If required, the internal pump can be turned off by pressing the N key.

Y/OK N/CHANGE

Static Sampling with the EGM-4

If static sampling is select ed, the user can inject samples direc tly into the s ample cell thro ugh the port labelled “Gas Out” rat her tha n ha v ing t he s am ple p umped through it. This is normally done using a syringe with 1/8” tubing o n the end which c an easily fit over t he “Gas Out” port on the EGM-4. For static measurements injected directly into the “Gas Out” port, we recommend a minim um volume of 5 ml. During the course of measurements, a warnin g is given 2 minutes and 1 minute prior to the instrument performing a ZERO followed by the pump turning on for a ZERO. On completion of the Analyzer ZERO, the pump will again switch off. By default, th e EGM-4 is set to dynamic sampling with the pum p on at all times. The general procedure for static measurements is as follows:

1. From the Main Menu, select 2SET, 3PMP.

2. With the “SAMPLE PUMP ON” message displayed, press key N to change to “STATIC SAMPLING”.

3. Press key Y to accept and then press key Y again to return to the Main Menu.

4. Press 1REC. The instrument will now perform a ZERO. Once the ZERO is complete, the pump will turn off.

5. Inject your sample (minimum of 5ml) direc tl y into th e Gas O ut port. We recommend a slow, steady injection rate of approximately 6 ml/second. Initially, the CO concentration will be higher (due to pressure) and then will drop to the actual concentration and shou ld remain stable. Once the re ading stabilizes, press the Y/R key to record the values. Rem ove the syringe from the “Gas Out” port to al low the system to flush properly.

6. After r ecording, pres s the 0/Z k ey to flush the sam ple cell a nd to allo w the instrum ent to perform a ZERO before injecting your next sample.

4AV

The outputs from the CO2 sensors are normally subjected to an averaging process. This consists of differ enc ing the cur rent read ing and t he s to r ed aver ag e r ead ing (b oth raw data). If the difference exceeds the average limit, then the current reading replaces the average.

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Operation

1REC:M 2INT: 0

1:LOCO2 = 250

AV. LIMIT = 6

Otherwise, the curr ent reading is incorpor ated int o the avera ge. T he average r eading is then linearized etc. to give the measured concentration. If AV is set to 0, then averaging is disabled giving instantaneous r eadings. The averaging band i s increased as AV is increas ed, up to a maximum of 999 units . The AV is automaticall y set to 1 unit for soil respiration and sta tic sampling measurem ents . T he AV def aults to 6 un its w ith out a prob e ( EGM-4 on its own). The default for the EGM-4 when used on its own is 0.3% of full scale. T herefore, for an EGM-4 calibrated to 2,000 ppm, the default value would be 6 ppm.

Press 4AV to change the AV.

Y/OK N=NEW VAL

If you want to change the AV value, press key N and enter a value up to a maximum of 999.

5RECD

This controls the recording in the EGM-4. Records can be recorded manually or automatically at set time intervals. Press Key 5 to set the recording type.

To change the recording f rom MANUAL (M) to AUT OMATIC (A) and v ice versa, press key 1. If M is displayed, the tim e interval (2INT ) is set 0 b y default. A k ey press of 1 will chang e the recording type to A (Auto matic) and the time interval (2INT) wil l change t o 1 (1 minute) by default. To change the ti me interval for automatic recordin g, press key 2 and enter a value (not to exceed 720 minutes ). Note, leading zeros are required for v alues less than 100 (i.e. 005 for 5 minutes).

The EGM-4 is set to MANUAL recording by default.

6ALM

There are both high and low alarm facilities built into the EGM-4. A 2 pin header type connector (CN6) is located on the internal EGM-4 circuit board for controlling the audible alarm. All EG M-4’s are currently supplied with the a udible alarm disabled as the jumper is fitted to just one pin on CN 6. To enable the audib le alarm, simpl y fit the jumper to both pins on CN6. For access and locatio n of CN6, see Inside the EGM-4 on page 47. A TTL level signal for low CO

is always output o npin 7 of the I/O connector whether the audible alarm

jumper is in place or not. Note, the alarm facilities are not available with Probe T ypes 7 or higher (i.e. porom eter and soil respiration) . Press key 3 to set t he Low and High CO

alarm

setpoints.

2:HICO2 = 2000

Setting the Low CO2 Alarm Setpoint

Press key 3 (3ALM) and key 1 to set the low CO2 al arm setpoint in ppm. The display will show ?????. Enter the require d value. Note, leading zeros are req uired for values less than 1000 (i.e. 00200 for 200). The EGM-4 is supplied with a factory default low alarm setting of 250 ppm . T he r eas on f or this is that a low CO following scenarios:

• Low or no air flow.

• Absorber column exhausted (soda lime).

value can be the r esu lt of one of the

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Operation

Error Code

Reported fault

Zero to low

CO2 < 250 ppm

Analyzer temperature out of range (too cold)

Analyzer temperature out of range (too hot)

RH > 90%

D/A 1V

Selects the maximum voltage output of the EGM-4 (1-5V)

2000

Corresponds to the CO2 concentration (ppm).

D/A 1V = 2000 ppm

• Zero valve failure.

• Source failure.

However, past history has shown that some customers want to work at lower CO concentrations. As a result , lower alarm s ettings can be set up by the user if required. If the low alarm is s et to 250 ppm, the low alarm operates when the s elf-check ing facility finds an y of the following system faults:

The above error codes are ac companied by corresponding dis plays and the error codes are written to the records. Note, with the por ometer and soil respir ation/canop y chambers (SRC 1, CPY-4 and CFX-1), the display warnings still occur but there is no alarm.

The low alarm signal comes out on Pin 7 and is buffered (i.e. able to drive a load).

Setting the High CO2 Alarm Setpoint

Press key 2 to set the high CO2 alarm setpoint. The display will show ?????. Enter the required value. Note, leadin g zeros a re requ ired f or v alues le ss than 1000 ( i.e. 00 900 f or

900). The default EGM-4 high a larm setpoint setting is 2000. As long as the high alar m is set to the maximum CO value, when the CO

ppm range of the instrument, the alarm is inactive. If set to a lower

concentration exceeds the high setting, the alarm will activate.

The high alarm signal comes out on Pin 13 and is not buffered.

7VOUT

Press key 7 (7VOUT) to check/set the analog voltage output. These settings control the voltage output from the D/A converter in the EGM-4.

Where:

The FSD (Full Scale Deflection) ana log output value can be set from 1 to 5V. Press key 1 and enter any value between 1 and 5 to s et the analog outp ut to the value req uired. Press key 2 if you want to change the C O As in the display above, the EGM-4 would be set up with an analog output of 0-1V corresponding to a measurement range of 0-2,000 ppm.

By default, the analog voltage outp ut is 0-5V. If the displayed values are correct, simply press the Y key to return to the 2SET menu.

Note. The voltage output must be set to 5V in order for the current output (4-20 mA) to work properly. If the voltage output is changed to any other value (i.e. 2, 3 or 4V), the current output facility will not work co rrectly and should not be used.

Y=OK 1/ 2 NEW VAL

concen tration cor responding to the a nalog output valu e.

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Operation

CO2 CONC = 2000

EGM-4

Pressure

In-line “T” piece

to vent excess

Gas In

Shut-Off

Excess gas of approx. 250 ml/min

3CAL

To calibrate the EGM-4, press key 3.

The EGM-4 will display a value. Before proceeding, it is critical that:

• The absorber column is properly seated in its manifold

• The soda lime is fresh.

• The EGM-4 has been on for at least 30 minutes.

• The Gas Out port is unobstructed.

• No accessories or sensors can be connected to the EGM-4 when recalibrating.

Connecting Calibration Gas To The EGM-4

During calibration, the sig nal fr om the CO2 detector is referenced aga inst a gas of known CO2 concentration. The EGM-4 calibration procedure uses two reference points:

1. Zero CO

2. Span Gas (a user-defined CO composition).

It is therefore vital t hat both of these ref erences are accurate. For greater accurac y, cylinder mixtures should be ac curate to +/- 1% and traceable to NIST standards. The zero gas will only be accurate if the soda lime in the absorber column is fresh.

Assuming that a calibration gas mixture is used to calibrate the EGM-4, follow these instructions:

1. To avoid exc ess pressure in the sample cell and pos sible damage to the Analyzer, you must connect the sample line with a “T” piece between the calibration gas mixture and the “Gas In” port on the EGM-4 as follows:

(generated from air that has been scrubbed through soda lime).

Port

CORRECT (Y-N)?

concentration, normally a cylinder of certified CO2

Regulator

CO2

Gas

Valve

Cylinder

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Operation

1:SCREEN DISPLAY

CO2 CONC = 1050

REC 0000 PLOT 01

2. The pres sure regulator s hould be se t to a very low pressure and there should be a slight flow excess gas ve nting from the op en “T” Piece (ap prox. 250 ml/m in). We recomm end using a flow rate from the gas cylinder of approximately 200-400 ml/min.

3. Press k ey N and enter the CO This value must m atch the certified CO

concentr ation of the calibration gas that you are us ing.

concentratio n of the calibration cylinder and be

similar or higher than the a nticipated meas urement range of the i nstrument (i.e. it is bes t to calibrate the instrument with a reference gas containing 350 - 450 ppm CO measuring around 350 ppm CO

when

4. The EGM-4 will then perform a ZERO. At completion of successful ZERO, a similar message to the following will be displayed.

KEY0 WHEN STEADY

5. At this point, all you are looking f or is that the CO

c oncentration is steady. Note, the

displayed value may not be the value you entered in step 1 above. When this value is steady (i.e. not changing by more than 1 ppm after 30 seconds), press the 0 key. Control is passed to the VOUT Set Menu to provide the opport unity to change the s cale factor if desired. If no change is desired, press key Y.

6. Calibration is complete. The new calibration and linearization constants are stored in non-volatile memory.

4DMP

Press key 4 to view/transmit stored data.

2:DATA DUMP 1-2?

Stored data can be v ie wed on th e ins trument LCD displa y or tra ns mitted to your PC computer using our data transfer s of tware. T he EG M-4 will store up to 1,000 rec ords in memory. Note,

when the memory is full, the oldest record will be overwritten each time additional records are taken. Also note that the record number restarts at 1 when the EGM -4 is powered off. Therefore, more than one record number 1 with different time stamp can exist in memory.

Screen Display

To view stored data on the LCD dis play, press key 1. The latest stored record is displayed first. Each record has 3 different displays associated with it as follows:

Display 1

Where:

REC Record Number PLOT Plot Number 04-01 Date (4 11:52 Time

04-01 11:52

day of January)

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Operation

C 950 H06.4

A0000 B0000 0000

Press the 8/X key to proceed to the next display:

Display 2

D0000 E0000

Where:

A mV signal from sensor (Pin 1). B mV signal from sensor (Pin 2). C mV signal from sensor (Pin 3). D mV signal from sensor (Pin 4). E mV signal from sensor (Pin 5).

Press the 8/X key to proceed to the next display:

Display 3

A 0992 P00

Where: C CO

concentration(ppm)

H Humidity (mb). Only if optional %RH/Temp sensor is present. A Atmospheric Pressure (mb) P Probe Type

A k ey p ress of 8 steps you through the 3 abo ve displays bef ore taking you to the next rec ord in memory. After all records have b een displ a yed, a m essage “No Mor e Record s In Stor e” is displayed before return ing you to the Main Menu. No te. A key press of Y will step you from one display to the same display for the previous record. For inst ance, if Display 3 of record number 5 is displ a yed on t he L CD, a k e y pre ss of Y will step you to Display 3 for the previous record (Record 4). Therefore, if you are only interested in viewing the CO

concentration for each record:

1. Press key 4 (4DMP).

2. Press key 1 (Screen Display).

3. Press the 8 key to display the CO

concentration for the last stored record.

4. Press the Y key to view previous records.

A key press of N ends the sc reen displa y. Note. If there are no stor ed recor ds, the message “NO MORE RECORDS IN STO RE” will be displayed bef ore returning you to the m ain menu. Note, some of the displays will vary according the probe type connected.

Data Dump

To transmit stored data f rom the EGM-4 to a PC, you mus t use the data transfer cable and software supplied with the system. Step by step ins tructions on transferring data from the EGM-4 to the PC are contained in the software Help file.

Transferring Stored Data Using The Windows® Based Software Program

Click on TransferW in.exe to load the s oftware suppl ied by PP S ystems to your local P C hard drive. Once the program is loaded successfully and from the Windows Task Bar:

1. Select Start, Programs, PP Systems and then Transfer

2. Click File, Preferences and select EGM-4 under Instrument Type.

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Operation

M/R Plot

No.

Rec

Day

Min

CO2

Ref

H20

Ref

RHT A B C D E F

G H AP

M 1 1

28 1 13

968 0 000.0

0000

991 0 R 1 2

28 1 13

930 0 000.0

0000

991 0 M 1 3

28 1 13

956 0 000.0

0000

991

M 1 4

28 1 13

941 0 000.0

0000

991

R 1 5

28 1 13

946 0 000.0

0000

991

M/R

M = Real Time Measurement R = Record from memory

Plot No.

0-99

Rec No.

1-9999

Day

1-31

1-12 (January - December)

1-24 (based on 24 hour clock)

Min(utes)

0-59

CO2 Ref

CO2 reading in parts per million (ppm = µmol mol-1)

H20 Ref

H2O reading in millibars (mb) (if optional %RH sensor is fitted).

RHT

Temperature of RH sensor (˚C) (if optional %RH sensor is fitted).

See Data Structure Based On Probe/Sensors on page 39.

3. Check the Com port selected and change if necessary (i.e. COM1,2,3 or 4).

4. Check Decimal separator to m ake sure that it matches your requirements . Data can

be separated by a period (.) or comma (,).

5. Click OK to proceed.

6. Ensure tha t the EGM-4 is in Dum p Menu (Ke y 4 from Main Menu). Pr ess ke y 2 Data

Dump on the EGM-4. On the EGM-4 “CONNECT TO PC ANY KEY TO SEND” should be displayed.

7. Select Transfer on your PC and enter in a file name (the .dat ex tension is assum ed

and does not need to be entered) an d click on Save. All stored data will be s tored to this file. On the PC, a message sim ilar to “Com Port 1 opened…. Awaiting EGM-4 data….” will be displayed.

8. On the EGM-4, press any key to transfer the data. When completed, the EG M-4 will return to the Ma in Menu and the PC screen will show

“Transfer of EGM-4 Records Completed X Recor d[s] received, Click in W indow to clear …” where X refers t the total number of records transferred.

Logging Data

In addition to transferring stored data from the EGM-4 to your local PC, the user can log measured data as well. In Log mode, you have the ability to log records automatically or manually.

For further description and instructions on the Windows PP Systems, please refer to the on-line help menus built into the software.

based software supplied by

Record Structure

A single record consists of 61 charac ters ( no spaces ). T he last char acter is a carriage r eturn. Real time and stored data is output in the following format:

Where:

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Operation

See Data Structure Based On Probe/Sensors on page 39.

Atmospheric pressure in millibars (mb)

Probe Type See 1REC on page 19 for more information.

Probe

Type

Description of Sensor

Connected

Each Column is described as follows

A B C D E F G

No Sensor Connected. as a stand alone IRGA.

STP-1 Soil Temperature Probe

PAR

%RH

Soil

HTR-2 %RH/Temp/PAR

PAR

%RH

Air

000.0

TRP-1/TRP-2

PAR

%RH

Air

000.0

PAR-1/PAR Sensor

PAR

0000

PAR-1 LUX

Solarimeter

Steady State Porometer

PAR

%RH

000.0

Temp

%RH

000.0

Flow

SRC-1 Soil Respiration

Chambers

PAR

%RH

Soil

SRDIV

+/- SR

OP-1/OP-2 Oxygen Sensor

50Y %RH/Temp Sensor

%RH

000.0

Temp.

000.0

CFX-1 Open System Soil

PAR

Evap

Air

Flow

+/- SR

01 = -

CPY-3 Canopy

PAR

Evap

Air

Flow

+/- SR

01 = -

CPY-4 Canopy

PAR

Soil

Air

+/- SR

01 = -

Output Data

Units

PAR

µmol m-2 s

-1

% RH

Evaporation Rate

mmol m2 s-1 x 1000

Temperature

˚C

Flow

ml min-1

GS (Stomatal Conductance)

mmol (H2O) m

² s-¹

SR Rate (Assimiliation)

SRC-1: g (CO2) m2 Hour

-1

CPY-3 & CFX-1: µmol m2 s

Note. If there are no s tor e d rec or ds, t he message “NO MORE R ECO RDS IN STORE” wil l b e displayed before returning you to the main menu.

Data Structure Based On Probe/Sensors

Please note. The data structure, particularly columns A-H described above, is dependent

upon the probe/sensor that is connected to the EGM-4.

The EGM-4 is being used

Probe or CH15T RH/T

Probe

Temperature/PAR Probe

(PMR-4/PMR-5)

Chamber and CPY-2 Canopy Assimilation

Respiration Chamber

Pin 1 0000

0000

00.00

0000

Pin 2 0000

000.0

0000

Rate 0000

Pin 3 0000

Temp.

000.0

Temp.

000.0

Temp.

000.0

Temp.

000.0

Pin 4 0000

Out

0000

Pin 5 0000

000.0

0000

000.0

0000

Rate

00.00

Rate

00.00

01/02/03

Multiplier

Rate 00=+

01 = -

Rate 00=+

Assimilation Chamber

0000

Further description of the data output is as follows:

CPY-2: g (CO2) m2 Hour-1 CPY-4: g (CO

EGM-4 Operator's Manual – Version 4.19

Rate 0000

Temp.

0000

- 39 -

Temp.

000.0

Temp.

000.0

) m2 Hour-1

0000

-1

000.0

0000

Rate

00.00

Rate

00.00

Multiplier

Rate 00=+

Page 40

Operation

DC (Change in CO2 concentration )

ppm

DT (Change in time)

seconds

+/-

In column H, if 00 is output, this represents increase in CO2 (respiration). If it is 01, it represents CO2 uptake).

Error

Code

Description

Possible Faults

Remedy

Normal Operation

Not Applicable

Zero read to low

• Pump Failure

• Refer to Air Sampling

on page 7)

CO2 less than 250

• Pump failure

• Refer to Air Sampling

on page 7)

Analyzer

• Possible thermostat

• Contact PP Systems.

on page 7)

Analyzer

• Possible thermostat

• Contact PP Systems.

on page 7)

In column G, a flow multiplier is output to provide true flow rate (1 or 10).

Error Cod

Error code inform ation is stored and output with data and can be located at the end of the data string. The following is a list of current Error Codes:

(<2500)

ppm

• Absorber column not properly fitted.

• Exhausted soda lime.

• Zero valve failure.

• Source/detector failure.

• Genuine low CO

concentration.

• Absorber column not properly fitted.

• Exhausted soda lime.

• Zero valve failure.

• Source/detector failure.

Pump on page 51.

• Fit properly into manifold.

• Change soda lime.

• Contact PP Systems.

(see PP Systems’

Contact Information

on page 7)

• Contact PP Systems. (see PP Systems’

Contact Information

Pump on page 51.

• Not Applicable.

• Fit properly into

manifold.

• Change soda lime.

• Contact PP Systems.

(see PP Systems’

Contact Information

on page 7)

• Contact PP Systems. (see PP Systems’

Contact Information

temperature < 50 ˚C

temperature > 60 ˚C

EGM-4 Operator's Manual – Version 4.19

failure.

- 40 -

(see PP Systems’

Contact Information

(see PP Systems’

Contact Information

Page 41

Operation

%RH > 90%

• If an RH sensor is fitted, a

• Contact PP Systems.

on page 7)

Battery voltage to low

• Battery voltage < 10.5v

• Re-charge battery

ZZZZZ

Stored Analyzer reading dur ing last zero.

CCCCC

Current Analyzer reading

ANLT

Analyzer temperature sensor reading.

HHHH

Reading of the internal humidity sensor (optional).

HTHT

Reading from the temperature sensor (optional).

INPA-E

Corresponds to the mV inputs from external sensors (A-E).

ATMP

Reading from the pressure transducer (mb).

CLEAR DATABASE

reading above 90% could mean condensation.

(see PP Systems’

Contact Information

EGM Serial Outputs

(For Use With WINDOWS Data Transfer Pr o gram or other terminal program)

The following data strings are output from the EGM-4 with no user intervention. On Starting: <SP>B, EGM4,Serial Number, Firmware version<CR>

<SP>=Space, <CR>=Carriage return. Then during the delay period at the start: <SP>I, NN <CR>

Where NN is the same as the count on the EGM display. During Warm up <SP>W,TT<CR>

Where TT is the cell temperature. During ZERO

<SP>Z,NN<CR> Where NN is the same as the EGM display count.

During Diagnostics a data string is transmitted through the RS232: <SP>D,ZZZZZ,CCCCC,ANLT,HHHH,HTHT,INPB,INPC,INPD,INPE,ATMP<CR>.

(These values are the reads from the A/D converters and have not been scaled.) Where:

5CLR

To clear data stored in memory, press key 5.

EGM-4 Operator's Manual – Version 4.19

(YY-N)?

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Operation

RESET TIME (Y-N)?

To clear the entire database, press the Y key twice. For data safety reasons, you will be asked to “Press Key 0 To Confirm”. Press the 0 key to clear. The message “Database Cleared” is displayed bef ore returning you to the main menu. If you do not want to clear the database, simply press the N key.

6CLK

To view/set the EGM-4 re al time clock, press the 6 ke y. The following message should be displayed:

The date is displayed as d ay/month/ year and the time is displ ayed on a 24 hour f ormat. The display above shows December 13, 2001 and 4:51 PM. If the time is correct, press the Y key. Otherwise, press key N and enter the appropriate date and time. Leading zeros must be entered if required for date and time (i.e. if the time is 8:00 AM, enter 08 for the hour).

! Note ! Do not forget to enter the date as day/month/year and the time based on the 24 hour format.

13-12-01 16:51

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Page 43

Diagnostics and Initialisation

CR:44049

Reading from 16 bit A/D convert er for CO2 detector. The CR valu e should read approximately 35000-45000 for CO2 concentration around 400 ppm .

Z:46132

Reading from 16 b it A/D c onverter during last Auto-Zero seq uence. The A/D

if fresh soda lime is

the CR value.

0/Z

Press key 0 to perform an Auto-Zero.,

CO2 Calibration Concentration

2000 ppm

Recording Type

Manual. No averaging of data.

Zero Type

Automatic

Checksum

123456

Analog Voltage Output

Memory

Reset to start of memory.

1:DIAGNOSTICS

CR:44049 Z: 46132

Diagnostics and Initialisation

The EGM-4 has a di agnostics and “Initialisation” feat ure built in for troubleshooting an d for setting system contr ols and calibratio n back to factory def ault. It is important to allow the EGM-4 to warm up for at least 30 minutes prior to checking system diagnostics. To check system diagnostics and to reinitialize the EGM-4, press key 0 with the Main Menu displayed. The following message is displayed:

Diagnostics

Press key 1 for system diagnostics and the following will be displayed:

Where:

2:INTIALISE

0/Z: ZERO N: QUIT

value for Z should read approximately 40000-50000 present in the absorber column. The Z value should always be gr eater than

Press Key N to return to the Main Menu.

Initialisation

This feature is available in the event of a bad or incorrect calibration, if a new EPROM is installed with a new “Chec ksum” value, or if the system locks up. Press key 2 to reinitialize the EGM-4. Very Important. Before initializing the EGM-4, you must dump all stored

records to your PC or they will be lost for good. All records will be cleared from system memory during Initialisation.

After pressing key 2, you will be pres ented with ???? on the displ ay. At this point, enter the code 0462. This will follo w with a “Database Cleared” message before returning you t o the Main Menu. At this point, your s ystem will be returned to its orig ina l factor y defaul t conditions (i.e. calibration, etc.). The EGM-4 system settings will automatically revert to:

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Page 44

Maintenance

The EGM-4 is virtually maintenance free. However, there are a few items that should be watched and cared for periodically.

Soda Lime Absorber Column

The soda lime absorber column is built into the EGM-4 and safely protected within the enclosure. It should not require any maintenance with the exception of the soda lime desiccant which will requir e replacem ent f rom tim e to tim e (See Soda L im e on page 44). T he black aluminium c ap, located on the back of the instrum ent, is fitted with an “O” ring with a grey foam filter between it and the d esiccant . The “ O” ring should be k ept fr esh by appl ying a slight smear of s ilicone grease f rom time to time. If this “O” ring gets to dry, it c ould crack or even break which will lead to a leak in the system and errors in Analyzer Z ERO. The black aluminium cap can then be removed and the contents emptied when required. When replacing the soda l ime, the column should be tappe d to ensure tight packing and the c ap replaced as found. Over t ime, the grey foam filter m ay requ ire r ep lac ement. If so, contact PP Systems (PP Systems’ Contact Information on page 7).

It is sensible to examine the absorber column each tim e the contents are replaced as any leakage of ambient air into the gas circ uit general ly causes error messages during “Autozero” operation or fluctuating CO

concentration during measurement.

Soda Lime

Soda Lime is suppli ed as self-indicati ng granules (1-2. 5mm) which turn fr om green to brown as it becomes exhausted. T his desiccant should b e replaced when it is t wo-thirds exhausted (brown). Soda Lime cannot be regenerated and should be discarded when exhausted. Frequent replacem ent should not be required under normal c ircumstances. The amount of change is highly dependent on the “Auto-Zero” frequency. Under normal operating conditions, this desiccant is changed approxim ately 1 time per month. See Soda Lime on page 44.

For accurate measur ements and calibration, it is absolutely critica l that the EGM -4 absorber column is not exhausted. If the soda lime is becoming exhauste d, it will cause the ZERO to be performed on non-ZERO air causing an error in the calibration.

! CAUTION !

WASH YOUR HANDS AFTER HANDLING SO DA LIME

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Maintenance

CHEMICAL COMPOSITION

Components

% W/W

Calcium Hydroxide

(Ca(OH)2) > 75.5%

Sodium Hydroxide

(NaOH) < 3.5%

Water

< 21.0%

Indicator (Inorganic Salt)

< 0.2%

PHYSICO-CHEMICAL DATA

Form

Granules

Color

Green (Exhausted : Brown)

Odor

None

Bulk Density

0.9 g/cm3

Solubility in Water

None

pH in Water

12-14

Incompatible Substances

Acids, Chloroform, Trichlorethylene

Hazardous Decomposition

Products

None

PROTECTIVE MEASURES,

Storage Conditions

Clean dry environment

Preferred temperature range

0 - 35 ˚C. Store away from direct heat/sun.

Protective Measures

Avoid inhaling dust. Wash hands after handling

Industrial Hygiene

Keep containers closed. Keep contents dry.

MEASURES IN CASE OF ACCIDENTS AND FIRES

Spillage

Contain material.

Wash down spillage with water.

Suit. Extinguishing Media

Water, CO2, Powder, Foam, Halon.

FIRST AID

Inhalation

Remove from exposure. Obtain medical attention if discomfort persists.

Skin Contact

Drench with clean water. Obtain medical attention if skin becomes inflamed.

Eye Contact

Irrigate thoroughly with clean water. Obtain medical attention.

Ingestion

Wash out mouth thoroughly. Obtain medical attention.

HAZARD LABELLING

Transport Codes

None required. Hazard Classification

None.

MAT ERIAL SAFETY DATA FOR SODA LIME

STORAGE AND HANDLING

Sweep or vacuum up. Transfer solids to metal or plastic container for disposal.

Drink water.

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Page 46

Maintenance

Remove These 4

Components

Servicing The EGM-4

Fuse

The EGM-4 circuitry is protect ed by a 1A (5x20 mm) fuse. This is located in a black fuse holder located at the back of the instrument (see page 11 for location). If this requires replacement, please ensure that the correct size and type of fuse is used.

It is very easy to determ ine if a fuse is good or bad. Usually, a bad fuse will b e burned out and visually obvious. The true test is to use an ohm meter. Place one lead fr om the ohm meter on one end of th e f u s e an d t he oth er l ead o n t h e o ppos i te end of the fuse. If it r eads 0, you have a good fuse. Anything else, the fuse is bad and should be replaced.

The EGM-4 enclosure must be removed in order to service the following items:

• Infrared Source

• EPROM

• Zero Valve

• 12V Lead Acid Battery

• Air Sampling Pump

Screws To Access Internal EGM-4

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Maintenance

Real Time Clock

EPROM

Notch On

Air Sample Pump

Zero Valve

Infrared

Current Output

Air In

Air Out Front Panel Retaining Nuts

Rear Panel Retaining Nut s/ Sc r e ws CN6 (Alarm)

Source

EPROM

(4-20mA)

(CN7, IOut)

Inside the EGM-4

Infrared Source

The infrared source shoul d last for many years and not requir e replacement. The obvious sign of failure is that it is not flashing when the system is powered. It is preferable to return the instrument to PP Systems for full factory recalibration after changing a f ailed source lamp. However, if that is not possible, a few checks can be made to insure that the analyzer is working properly after changing a source lamp in the field.

1. Ensure that the EGM-4 is not connected to any power source and is turned of f .

2. Disconnect the infrared source electrical connector located at CN13 (Source) by pulling up on it.

3. Rem ove the 4 small screw s that secure the inf rared source to the end of the sample cell and remove it.

4. Fit the new infrared sour ce to the end of the sam ple cell aligned t o fit in the n otch in the sample tube and sec ure it in place b y the 4 small screws. Be careful handling

the IR source. You do not want to touch the bulb with your fingers. Also, do not overtighten the screws.

5. Connect the new infrared source electrical connector to CN3 on the circuit board. The orientation does not matter.

6. Power up th e EGM-4 and allo w it to run warm up f or 30 minutes. After the warm up period, check the raw IRGA A/D readings with CO

-free air.

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Maintenance

Checking EGM-4 Raw A/D Readings

On the EGM-4, monitor th e raw A/D readings on the dis play. To do so from the m ain menu (1REC 2SET 3CAL, etc.):

1. Press Key 0 (to go into system diagnostics)

2. Press Key 1 (Diagnostics)

The display will sho w the current A/D readings for the CO “Zero” mode. Press key Z to check the analyzer zero. At this point, CO passing through the anal yzer. W hen completed, the raw A/D reading for the analyzer zero will be displayed in the upper right hand corner (i.e. Z:51235).

The raw A/D reading with CO Once the raw A/D readi ng with CO

-free air must be greater than 40,000 and less than 52,000.

-free air is in the range 40,000 to 52,000, the instrument

should perform normally and accurate ly. If you are un abl e t o achieve raw A/D readings in the range of 40,000 to 5 2,000 after replacement of the inf rared source, the SOT resistor (R38) should be changed. The SOT resistor is located o n standoffs near the detector end of the sample cell making it eas y to identif y on the PC B and f or eas y solderin g. T he resist or can b e any value between 0 ohm and 10 00 ohms that m akes the zero re ading between 4 0,000 and 52,000. Lower SOT resistor values incre ases the g ai n and inc reas es the zer o A/D reading. If you are unable to achieve raw A/D readings in the range of 40,000 to 52,000 after replacement of the inf rared sourc e, contac t PP S yste ms f or advice ( see PP System s’ Contac t

Informationon page 7).

At this point, it would be pr udent to perform a singl e point calibration with a r eference gas if possible (See 3CAL on page 35).

analyzer for both “Measure” and

free air will be

EPROM

The firmware and f actory measured calibrat ion f ac tor s f or the EGM-4 are stored o n a memory chip commonly referred to as an EPROM inside the instrument. This should never require maintenance but it may need to be replaced if the system is upgraded.

The EPROM that is us ed in the EGM-4 mus t be protected f rom st atic electr icit y. As a res ult, there are several precaut ions that the customer s hould take before removing EP ROMS. The risk of damage can be m inimized by earthing both the operator and the la b bench surface. This can be done by covering the surface of the bench with a conductive material (e.g. aluminium foil) that is e lectr ical l y connec te d to an earthing point such as a metal water pipe or tap. The operator should also be earthed using a wrist strap or by holding a wire that is connected to the same earthed point. Please contact PP Systems for further information.

Once suitable earth ing arra ngements have been m ade , the EGM-4 enclosure can be opene d to gain access to the circuit board containing the EPROM. T he position of the EPROM is shown above.

Each EPROM is locate d in a spec ific or ientat ion. B efore s tarting t o rem ove the c hip, not e the position of the notch on the end of the chip relative t o the rest of the instrument. Using a small, flat screwdriver, ge ntly pry the EPROM up until it is removed from its socket. W hen fitting the new EPROM to t he socket, be careful not t o bend any pins. Place th e EPROM in the socket (noting the notc h on one end of the EPR OM) and gently press down to secure in place.

Very Important. After replacing the EPROM, you should reinitialize the instrument (See

Initialisation on page 43).

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Maintenance

Manufacturer

Enersys

Type

Lead Acid

Voltage

12V

Nominal Capacity @ 20 hr.rate (Ah)

2.0 Ah Terminals

Faston Tab 0.187”

Housing

ABS Resin

Dimensions

14.6cm L x 8.8cm W x 2cm D

Weight

0.7 kg

If the battery is stuck, retaining nuts, gently push back of battery

Red (Positive) Charger Lead

Blue (Negative) Charger Lead

ZERO Valve

If it is suspected that the Z ERO v alve is n ot f unc tio nin g pr operly, we recommend r etur ning the EGM-4 to our factory for r epair as this item is soldered d irectly to the PC075 circ uit board. Contact PP Systems (see PP Systems’ Contact Information on page 7).

12V Lead Acid Battery

Some EGM-4’s are suppl ied with a 12V 2.0 Ah sealed, rechar geable, lead ac id battery and it should last for sev eral years as long as it is properly maintained. Bas ed on manufacturer’s data, the battery is non-spillable (qualified to non-spillable UN2800 standards) and can be used in any orientatio n. It has a f loat d esign life of 5 years. I t sho uld be c heck ed per iodical ly to ensure that it takes up char ge. Measuring the voltage across the term inals of the battery after it has been charged overnight can assess this.

If the battery is not fully charged after 12 hours, first check that the 1A fuse is ok . This fuse protects the charging circuit and if blown, the internal battery will not take a charge.

Please Note. The internal 12V battery should always be fully charged before long-term storage. If it is stored i n a low or discharged state, it is possibl e that it will become deepdischarged. If this occurs , the charge c apacit y of the batter y is perm anently redu ced and will require replacement.

12V Lead Acid Battery Specification

Removing The 12V Lead Acid Battery

When removing the battery, firs t ensure that th e power to th e EGM-4 is turned off . The front panel may need to be removed to s lide the batter y out of its compartm ent if it is stuck. Next, remove the red (positive) and blue (negative) charger leads from the battery.

remove the front panel pull panel forwards, and through hole provided.

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Maintenance

Manufacturer

Sanyo

Type

NiMH

Voltage

12V

Nominal Capacity @ 20 hr.rate (Ah)

4.0 Ah Terminals

Faston Tab 0.187”

Housing

Shrink wrap cells

Dimensions

13cm L x 8.5cm W x 1.5cm D

Weight

0.5 kg

Three

Slide the new batter y into the batter y compartm ent, connect the c harger leads c orrectly (Re d = Positive, Black = Negative) and refit the enclosure.

12V NiMH Battery

Some EGM-4’s are supplied with a 12V NiMH, rechargeable battery and it should last for several years as long as it i s pr operly maintained. It shou ld b e c hecked periodicall y to ens ure that it takes up c harge. Measuring the voltage ac ross the term inals of the batt ery after it has been charged overnight can assess this.

If the battery is not fully charged after 12 ho urs, first check that the 1A fuse is ok . This fuse protects the charging circuit and if blown, the internal battery will not take a charge.

Please Note. When storing the instrument for long periods, the internal 12V NiMH battery will slowly discharge over tim e regardl ess of the s tate of c harge. Ther efore you m us t ensure th at you charge the instrument fully prior to next use.

12V NiMH Battery Specification

Removing The 12V NiMH Battery

When removing the batt ery, first ensure that the p ower to the EGM-4 is turned off. W ith the enclosure and back panel removed, simply pull out the battery pack as shown below and locate the three term inal connections. The fr ont panel may need to be rem oved to slide the battery out of its compartment if it is stuck.

Terminal Connections

Next, remove the red, yellow and black terminal connections from the internal leads and remove the battery pack. To replace, simply slide in the replacement battery pack and connect up the three leads appropriately.

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Maintenance

Connect the pump to a 6-12V source and fit a 30mm tube to the pump inlet.

It is,

Hold the pump above a be aker of isopr opyl alcoho l and dip the t ube into the a lcohol (See

Alcohol

Pump

Air Sampling Pump

The EGM-4 is fitted with a s ealed, r otary vane pump to sample the refer ence air . Rotary vane pump components wear wi th prolonged use and m aterial from the vanes ma y build up within the pumps. This can e ventually reduce the pumping ef ficiency or even cause them to stop running. If t he pump is not running, the first an d simplest thing to do is tap it gentl y with a small screwdriver or pe n an d s ee if that gets it up a nd running. In many inst ances , this is a ll it takes. The normal signs of a bad pump are as follows:

1. Noise. A worn pump usually sounds rough or vibrates.

2. Temperature. The outer casing is hot when touched with your fingers.

Replacing The Air Sampling Pump

It is very easy to replac e a bad a ir s ampling pump. First, tr ace the elec trical connection to th e pump and disconnect the 2-pin connector from the terminal on the EGM-4 circuit board. Secondly, the electrical c onnector is rem oved by gentl y bending back the c onnector lock and sliding out the connector. Please note the orientation of the red and black wire for correct re-fitting of the pump. The pump itself is secured in position by the gas tubing connections. Finall y, rem ove the tubing f rom the inlet and outlet ports on the pump and lif t out.

Fit the new pump making sure that:

1. The flat back part of the pump sits flush on its manifold.

2. Connec t the inlet t ubing to the inlet port and the outle t tubing to the out let port on the pump.

3. Finall y, the 2-pin electric al connector shoul d be reconnected in t he same orienta tion. The two notches on the connector latch with the corres pond ing lock.

Cleaning The Air Sampling Pump

During prolonged opera tion, the vanes inside t he pump will wear and de posit material inside the pump. It is sensible to clean the pump by periodically flushing it with with isopropyl alcohol. The following procedure can be adopted:

(i.e. the EGM-4 can be used to supply power via the pump electrical connector.

however, essential that the flushing is performed outside of the instrument to avoid spillage into it).

below). Run the p ump to draw alcohol through it. A small roll of cotto n wool in the inlet pipe can act as a filter for the re-circulating alcohol.

Electrical

Connector

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Maintenance

Run alcohol through the pum p for a minute or two to e nsur e that an y m aterial is r em oved.

than usual.

If the pump is not running or appears to be s eized, it may be freed b y tapping it with a small screwdriver or on the bench or by reversing the voltage to run it backwards.

When finished, run t he pum p in air for at least 15 m inutes t o allow any resid ual alcoh ol to eVaporate. Ideally, let the pum ps dry outside of the EGM-4 o vernight. If the pumps are reconnected prematurely, the absorber chemical (soda lime) will be exhausted quicker

In-Line Filter Assembly (Hydrophobic)

The In-Line Filter Assembly (Hydrophobic) is commonly used with the EGM-4 especially when used with the SRC-1 Soil Respiration Chamber and CPY-2/CPY-4/CPY-3 Canopy Assimilation Chambers. It is fitted with a 3 micron PTFE hydrophobic filter and “O” ring ensuring proper sea l. It is ver y important t hat this be chec ked frequent ly for s igns of dir t/dust and water. The entire assembly should be replaced as necessary.

Part No. 10045-1 Filter Assembly (Hydrophobic)

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Consumables and Spares for EGM-4

STD005

12V 2.0 Ah Lead Acid Battery (EGM-1/2/4)

STD535

12V NiMH Battery Pack Assembly (EGM-4)

STD511

Mains Charger for EGM-4 (does not include mains cable)

STD007

Self Indicating Soda Lime, 1.0 kg

20218-1

Absorber Column Plug

30013-10

“O” Ring for Absorber Column Plug

20041-3

Absorber Column for EGM-4

STD076

Sealed Miniature Rotary Pump (ASF)

30032-1

Solenoid Valve (SBA-4, EGM-4, WMA-4)

PC073-1

EGM/SBA/ WMA Infr a -Red Source (Low Range Instruments)

PC073-2

EGM/SBA/ WMA Infr a -Red Source (High Range Instruments)

10020-1

IRGA Tubeset Assembly-Long (For SBA-4, EGM-4, WMA-4, TPS-1 & TPS-2)

10020-2

IRGA Tubeset Assembly-Short (For SBA-4, EGM-4, WMA-4)

STD053-1

20mm Fuse, 1A (Qty. 5)

STD070

RS232 Ribbon Cable (9 pin I/F) for EGM-4

STD521

USB to Serial Adapter

10045-1

Filter Assembly (Hydrophobic)

Consumables and Spares for EGM-4

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User Notes

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