Hanna Instruments HI 964400 User Manual

Instruction Manual

HI 964400

Microprocessor Bench

Dissolved Oxygen Meter

This Instrument is in Compliance with the CE Directives

www.hannainst.com

Dear Customer, Thank you for choosing a Hanna Instruments

Product. Please read this instruction manual carefully

before using the instrument. This manual will provide you with all the nec-

essary information for the correct use of the instrument, as well as a precise idea of its versatility in a wide range of applications.

This instrument is in compliance with directives EN 50081-1 and EN 50082-1.

TABLE OF CONTENTS

Preliminary Examination............................. 1

General Description .................................... 1

Functional Description Probe...................... 3

Functional Description of HI964400 ............ 4

Specifications of HI964400 ......................... 6

LCD Functional Description ........................ 7

Operational Guide....................................... 7

D.O. Calibration ........................................ 17

Temperature Calibration ............................ 21

Altitude Compensation.............................. 23

Salinity Compensation.............................. 25

Temperature Compensation ...................... 25

Logging Function ...................................... 26

Interface with PC ...................................... 30

Probe & Membrane Maintenance ............. 31

Additional Information ............................... 33

Accessories .............................................. 43

Warranty ................................................... 44

CE Declaration of Conformity ................... 45

ISO 9000 Certified Company since 1992

PRELIMINARY EXAMINATION

Remove the instrument from the packing material and examine it to make sure that no damage has occurred during shipping. If there is any damage, notify your Dealer.

Each bench D.O. meter HI964400 comes supplied complete with:

• HI 76407/2 D.O. probe with 2 m (6.7') cable

• HI 76407A membrane cap (2 pcs)

• HI 7041S electrolyte solution (30 ml)

• 12 VDC power adapter (HI 710005 or HI 710006)

• dust cover.

Note: Save all packing material until you are

sure that the instrument functions correctly. All defective items must be returned in the original packing with the supplied accessories.

GENERAL DESCRIPTION

HI964400 is a bench microprocessor-based,

logging meter for Dissolved Oxygen measurements.

It can store in memory up to 99 lots with up to 8,000 readings. These readings can be transferred to a computer system for elaboration or permanent storage.

Dissolved oxygen is indicated in ppm (parts per million) or in %.

Temperature is compensated for by the meter's ATC circuitry. Salinity compensation in water allows direct determination of dissolved oxygen in saline waters and the altitude compensation readjusts for the altitude variance.

The dissolved oxygen probe has a membrane covering the polarographic sensors and a builtin thermistor for temperature measurements and compensation.

This permeable PTFE membrane isolates the sensor elements from the testing solution, but allows oxygen to pass through. When a voltage is applied across the sensor, oxygen that has passed through the membrane reacts causing a current flow, and hence determining a reading.

FUNCTIONAL DESCRIPTION PROBE

7 8

1. D.O. Probe

2. Protective Cap

3. Watertight Shielded Cable

4. Polypropylene Probe Body

5. Temperature Sensor

6. O-Ring Seal

7. Silver Chloride Anode

8. Platinum Cathode (sensor)

9. Oxygen Permeable PTFE Membrane

10. Membrane Cap

FUNCTIONAL DESCRIPTION OF HI964400

THE FRONT PANEL

1. Liquid Crystal Display

2. Keyboard:

ALT key to display altitude settings CAL key to enter or exit the calibra-

tion mode; to enable or disable the date or time settings; to start or exit the D.O. logging mode

CFM key to confirm the calibration val-

ues

COMM key to display the RS232C baud

rate and command prefix

DATE key to display the date LOG key to display the lot number on

the primary LCD and the page number on the secondary one. Press again to display the sample number of the lot

! key to select the calibration value;

to set date, time, logging interval; to set the altitude and the salinity factors; to set the baud rate and command

prefix for communication to PC

NaCl key to display salinity settings OFF key to turn the meter on off ON key to turn the meter on RANGE key to select dissolved oxygen

measurement mode in ppm or in %

TEMP key to select temperature mea-

surement mode

TIME key to display the time

" key to select the calibration value;

to set date, time, logging interval; to set the altitude and the salinity factors; to set the baud rate and command prefix for communication to PC.

THE REAR PANEL

1. Socket for D.O. Probe

2. Reset Button

3. RS 232C Connector

4. DC Power Socket (for HI710005 or HI710006)

Unplug the meter from the power supply before replacing the fuse.

SPECIFICATIONS OF HI964400

Range D.O. ppm 0.00 to 45.00

Resolution D.O. ppm 0.01

Accuracy D.O. ±1.5% of full scale

Typical EMC D.O. ±1.5% of full scale Deviation Temp. °C ±0.5

Calibration D.O. single or double point at 0%

Altitude Compensation 0 to 1,900 m (6,230')

Salinity Compensation 0 to 40 g/l

Temperature Compensation 0.0 to 50.0°C (32 to 122°F)

Probe HI76407/2 with

Logging Interval 1, 15, 30 seconds

Computer RS 232C (optoisolated) Interface

Power Power socket for 12 VCD Environment 0 to 50°C (32 to 122°F);

Dimensions 230x170x70 mm

Weight 1 kg (2.2 lb.)

Response Time The response time is approximately

20 seconds for a 95% reading at a constant temperature of 25°C. The response time for low oxygen readings or at low temperature is approximately 40 seconds. Allow more time to obtain more accurate readings.

D.O. % 0.0 to 300.0

Temp. °C 0.0 to 50.0

D.O. % 0.1

Temp. °C 0.1

Temp. °C ±0.5

(HI 7040) and 100% (in air)

Temp. °C single point or double point

at 0.0°C and/or 50.0°C

Resolution 100 m (328')

Resolution 1 g/l

2 meters (6.7') cable

or 1, 2, 5, 15, 30, 60, 120,

180 minutes

95% RH

(9.1x6.7x2.7")

LCD FUNCTIONAL DESCRIPTION

Pri

mary Display

DATEppm TIME

CFM MEM WRONG CAL LOG

BUF

°C

1 2

INTV

m S

Secondary Display

OPERATIONAL GUIDE

POWER CONNECTION

Plug the 12VDC adapter to the meter and to the mains.

HI964400 uses an EEPROM to retain the D.O. calibration and temperature calibration as well as the serial communication setting. The instrument will store the respective data after a calibration or serial communication setting, even when it is not plugged-in.

PROBE CONNECTION & PREPARATION

To prepare the instrument for use, connect the D.O. probe to the meter securely by aligning the pins with the socket located on the back of the meter, pushing the plug in and tightening the threaded ring.

All probes shipped from Hanna Instruments are dry. To hydrate the probe and prepare it for use, connect it to the meter and proceed as follows.

1. Remove the red and black plas-

hipping

cap

tic cap. This cap is for shipping purposes and can be thrown away.

2. Wet the sensor by soaking the bottom 2½ cm (1") of the probe

black

red

in electrolyte (HI 7041S) for 5 minutes.

3. Rinse the membrane cap (HI 76407A supplied in the kit with the meter) with electrolyte solution while shaking it gently. Refill with clean electrolyte solution.

4. Gently tap the sides of the membrane cap with your finger tip to ensure that no air bubbles remain trapped. To avoid damaging the membrane, do not tap the membrane directly on the bottom.

FILL FIRST

THEN TAP

5. Make sure that the rubber O-ring sits properly inside the membrane cap.

THEN SCREW

BACK ON

6. With the sensor facing down, slowly screw the cap clockwise. Some electrolyte will overflow.

When not in use and during polarization (see below), place the protective transparent cap supplied in the kit with the meter.

TURNING THE METER ON

To switch the meter on, press

the ON key and let the probe in the auto-conditioning (polarization) mode before proceeding. After approximately 5 minutes, the instrument can be calibrated (see page 17).

If the probe is disconnected, the meter will display "----".

ppm

°C

This also indicates the possibility of a broken probe cable.

PROBE POLARIZATION

The probe is under polarization with a fixed voltage of approximately 800 mV.

Probe polarization is essential for stable measurements with the same recurring degree of accuracy.

With the probe properly polarized, oxygen is continually "consumed" when it passes through the sensitive diaphragm and dissolves in the electrolyte solution contained in the probe.

If polarization is interrupted, the electrolyte solution continues to be enriched with oxygen until it reaches an equilibrium with the surrounding solution.

Whenever measurements are taken with a non-polarized probe, the oxygen level revealed is both that of the tested solution as well as that present in the electrolyte solution. This reading is incorrect.

The calibration of this instrument is very simple.

Before proceeding with the calibration make sure the probe is ready for measurements (see page 8), i.e. the membrane cap is filled with electrolyte and the probe is connected

to the meter and properly polarized. For an accurate calibration, it is recommended

to wait for 5 or 10 minutes to ensure precise conditioning of the probe.

Keep the protective cap on during the polarization time and remove it for the calibration and the measurements.

Follow the calibration procedure on page 17.

D.O. MEASUREMENTS (in ppm or in %)

Make sure the meter has been calibrated (see page 17) and the protective cap has been removed.

Salinity and Altitude compensation

If the sample contains significant concentration of salinity or if you are performing measurements at an altitude different from sea level, the readout values must be corrected, taking into account the lower degree of oxygen solubility in such occasions as explained on pages 23-25.

Remember to set the altitude and/or the salinity before taking any D.O. measurements. The meter will automatically compensate for these factors.

Taking measurements

Immerse the tip of the probe in the sample to be tested. Make sure the temperature sensor is also immersed.

Press the RANGE key to display D.O. measurements. Allow approximately one minute for the meter to stabilize and read the

ppm

value of dissolved oxygen on

the display.

RANGE

Press the RANGE key to change the reading from ppm to % and vice-versa.

RANGE

For accurate dissolved oxygen measurements a water movement of 0.3 m/sec is required at a minimum. This is to ensure that the oxygen-depleted membrane surface is constantly replenished. A moving stream will provide adequate circulation.

The use of a magnetic stirrer to ensure a certain velocity in the fluid is recommended. In this way, errors due to the diffusion of the oxygen present in the air in the solution are reduced to a minimum.

At all times, the time necessary for thermal equilibrium to occur between the probe and the measurement sample must be allowed (a few minutes if the temperature difference is only several degrees).

TAKING TEMPERATURE MEASUREMENTS

The probe has a built-in temperature sensor. Press the TEMP key to display the measured

temperature on the secondary display.

TEMP

°C

Allow the probe to reach the thermal equilibrium before taking any measurement. Reaching thermal equilibrium can take several minutes. The greater the difference between the temperature at which the probe was stored and the temperature of the sample, the longer the time will be.

If "----" is displayed, it indicates that the D.O. probe is not properly connected or the

°C

temperature is out of range. This also indicates the possibility of a broken probe cable.

SETTING THE DATE AND THE TIME AND THE LOGGING INTERVAL

Press the DATE key to display the date. The month and the day will be displayed on the primary LCD, the year on the secondary one.

DATE

Press the CAL key to enter the setting mode, the month starts blinking.

CAL

DATE

Use the UP or DOWN arrow keys to select the month.

Press the RANGE key, the day starts blinking.

DATE

RANGE

Use the UP or DOWN arrow keys to select the day.

Press the RANGE key and the year on the secondary LCD will blink.

RANGE

DATE

Use the UP or DOWN arrow keys to select the year.

Press the CAL key to

CAL

exit the date setting mode.

+ 33 hidden pages