B&C Electronics OD 7685.110 INSTRUCTION MANUAL

CERT. N. 9115 BCEL

INSTRUCTION MANUAL

UNI EN ISO 9001:2000

OD 7685.110

OPTICAL D.OXYGEN CONTROLLER

D.O. scales: 0/400 - 0/200,0 %air
0/400 - 0/200,0 mmHg
0/40 - 0/20,00 ppm
0/40 - 0/20,00 mg/l

Temperature: -2/+52 °C

-28,4/125,6 °F

Option

S/N

REP N°

Power supply: 110/220 Vac

Software: R2.0x

Cod. 280067622 - Rev. A

B&C Electronics Srl – Via per Villanova 3 – 20040 Carnate (MB) – Italy P.IVA 00729030965

Tel [phone] – Fax [phone] [e-mail] - www.bc-electronics.it

B&C Electronics OD 7685.110

Index

1 DESCRIPTION 3

1.1 Measuring system ...................................................................................................................3

1.2 Optical D.O. measuring principle...........................................................................................4

1.3 Sensors and accessories ..........................................................................................................4

2 SPECIFICATIONS 5

2.1 Functional specifications ........................................................................................................5

2.2 Technical specifications..........................................................................................................7

2.3 Physical description..............................................................................................................11

3 OPERATING THE SYSTEM

12

3.1 Keys function........................................................................................................................13

3.2 Readout sequences................................................................................................................14

3.3 Calibration sequences ...........................................................................................................16

3.3.1 Zero and sensitivity calibration ......................................................................................16

3.3.2 Secondary parameters calibration...................................................................................20

3.3.3 Temperature calibration..................................................................................................22

3.3.4 Set point A and B............................................................................................................23

3.3.5 On/Off parameters ..........................................................................................................24

3.3.6 Auto clean parameters ....................................................................................................25

3.3.7 Visualizations .................................................................................................................27

3.3.8 Configuration..................................................................................................................28

3.3.9 Keyboard locked/unlocked .............................................................................................28

3.3.10 LCD contrast...................................................................................................................29

3.3.11 Main display ...................................................................................................................29

3.3.12 Temperature measuring unit...........................................................................................29

3.3.13 Access number................................................................................................................29

3.3.14 Measuring unit................................................................................................................30

3.3.15 Software filter LARGE...................................................................................................30

3.3.16 Software filter SMALL...................................................................................................30

3.3.17 Input related to the analog output Nr 1...........................................................................30

3.3.18 Analog output Nr1 parameters........................................................................................30

3.3.19 Input related to the analog outpt Nr 2.............................................................................30

3.3.20 Analog output Nr 2 parameters.......................................................................................31

3.3.21 Set-point A function .......................................................................................................31

3.3.22 Set-point B function........................................................................................................31

3.3.23 Cleaning function ...........................................................................................................31

3.3.24 Number of clearing cycle................................................................................................31

3.3.25 Compressor charge time (relay D off)............................................................................31

3.3.26 Compressor discharge time (relay D on)........................................................................32

3.3.27 Hold ................................................................................................................................32

3.3.28 Access number................................................................................................................32

4 INSTALLATION

33

4.1 Physical installation..............................................................................................................33

4.2 Electrical installation ............................................................................................................33

4.2.1 Connecting the optical DO probe with the built in temperature sensor .........................33

4.2.2 Connecting the relays .....................................................................................................34

Instruction manual - Rev. A - 07/09

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B&C Electronics OD 7685.110

4.2.3 Connecting the analog output .........................................................................................34

4.2.4 Checking.........................................................................................................................34

5 PREVENTIVE MAINTENANCE 35

WARRANTY CERTIFICATE ..............................................................................................................38

REPAIR .................................................................................................................................................38

TECHNICAL SUPPORT ......................................................................................................................39

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B&C Electronics OD 7685.110

1 DESCRIPTION

1.1 MEASURING SYSTEM

The Dissolved Oxygen monitoring system consists of two parts:

- the measuring/regulating instrument which is discussed in this instruction manual

- the optical dissolved oxygen probe

The system could be implemented with additional devices for field application:

recorder, remote display, PID regulators, sensor cleaner.

Instrument

This instrument carries out the following functions:

1) dissolved oxygen measuring when connected to the sensor

2) manual/automatic d.oxygen regulation, if suitable devices are connected to the output relays

3) temperature measuring, if an RTD Pt1000 is connected

4) manual or automatic compensation of temperature, pressure, salinity and relative humidity effects

6) D.O. and temperature acquisition, when connected to a recorder or a data logger

7) sending data via a serial interface, if the 091.701 option "RS232" is installed

8) external device activation for the sensor cleaning

Sensor

The B&C Electronics OD 8382 optical DO sensor or special galvanic sensor are suitable for this
instrument.

The sensor installation should allow a continuous contact with the sample, in a position with sufficient
stirring and exchange of sample.

In some applications the use of sensor cleaning devices is suggested.

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B&C Electronics OD 7685.110

1.2 OPTICAL D.O. MEASURING PRINCIPLE

A light beam of a specific wavelength is sent to a special fluorescent layer in contact with the sample.
The absorbed light energy is partially released as a light pulse with an higher wavelength.
This phenomena is called fluorescence.

If oxygen molecules are in contact with the sensing layer, the fluorescing is reduced (quenching).

By measuring the amount of quenching it is possible to determine the oxygen concentration.

The advantages of this measuring method are the absence of electrolyte and membrane, the possibility
to measure the oxygen concentration in water or in air, a not sensitivity to the flow, and a good
sensitivity in a low oxygen concentration.

1.3 SENSORS AND ACCESSORIES

To be ordered separately:

OD 8382 Auto clean optical DO probe, 10 m cable

OD 8112 Pressure air cleaner+controller

BC 931.2 Enclosure for one unit. IP65

BC 931.3 Enclosure for two units. IP65

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B&C Electronics OD 7685.110

2 SPECIFICATIONS

2.1 FUNCTIONAL SPECIFICATIONS

Input

The instrument accepts input from the OD 8382 optical DO probe or the AT amplified galvanic cell.
A second input is provided for 2 or 3 wires Pt1000 RTD temperature sensors.

Temperature compensation

The unit is supplied with manual or automatic temperature compensation and temperature
information may be displayed on the LCD.
The instrument detects of the absence or malfunctioning of the temperature sensor and automatically
switches to manual compensation.

Secondary parameters

The unit is supplied with pressure, salinity and relative humidity manual compensation.

Measuring ranges

The input range may be selected in PPM, mg/l, % air saturation and mmHg partial pressure.
The temperature range is selectable in °C or in °F.

Dual Analog output

Either a 0/20 mA or 4/20 mA isolated output may be selected, for use as an interface with computers
or data loggers.

A special routine allows selection of the analog output range.
The output current may be set anywhere from 0 to full scale.

Control relays

The D.O. monitor is equipped with two SPDT control relays.
Each control relay may be programmed for set-point, high/low, hysteresis or delay time actuation.
When the unit is configured as main display DO +SET, the full display indicates the current settings
and current status of each relay.

Cleaning function

The instrument features two relays (C-D) for autocleaning cycle.
The cleaning function may be activated automatically or manually.

The user may select:

- cleaning time

- holding time

- cycle repetition time

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B&C Electronics OD 7685.110

During the CLEAN and HOLD time:

- flashing messages will appear

- analog outputs are maintained in hold

- relays A and B are deactivated

Calibration mode

The instrument may be automatically calibrated in air.

Manual calibration may also be performed.

Software filter

The unit is provided with a dual programmable software filter, to be inserted when the readout is not
stable.

Configuration

The electronics for the D.O. monitor system are designed to be as flexible as possible.

A number of programming functions are provided in the configuration menu and are protected by an
access number, which must be entered to allow changes in this setting.

The main display can be configured in order to show the D.O. and temperature values or the D.O.
value and set point status.

Keyboard lock

The keys on the front panel of the monitor can be used for both changing the display and for
calibrations and set-point adjustments.

When the monitor is shipped, all functions are accessible.

However, the adjustment and calibration functions may be locked in order to prevent unauthorized
adjustments to the instrument.

Options

091.404 24 Vac power supply

091.4143 9/36 Vdc power supply

091.701 RS232 isolated output
The output sends the data (D.O. value, °C) to the serial port

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B&C Electronics OD 7685.110

2.2 TECHNICAL SPECIFICATIONS

The Default values are correspondent to the factory calibration values.
Parameters marked by "*" can be modified in the Configuration procedures.

1) DO SENSOR

* Main display: DO+SET/DO+TEMP

Input: from optical DO sensor
or from amplified ATI galvanic cell
Input signal at 20 °C (68 °F): 83.2/1040 mV
Sensor sensitivity: 20%/250 %
Temperature compensation: internal table

Reference temperature: 20°C (68 °F)
* Scales: % air saturation: 0/400 - 0/200.0 % air
ppm: 0/40.0 - 0/20.00 ppm
mg/l: 0/40.0 - 0/20.00 mg/l
Partial O2 pressure: 0/400 - 0/200.0 mmHg

Zero adjustment: +/- 40 mV
Sensitivity adjustment: 200/250%
Display resolution at 20°C: 1/1000
Auto calibration (function of temp.-press.-UR)
Manual calibration (through up/down keys)

Software filter 90% RT:
* Large signal variation: 0.5/50.0 seconds
* Small signal variation: 0.5/50.0 seconds

2) SECONDARY PARAMETERS

Pressure: 500/800 mmHg 760 mmHg
Salinity (chlorides): 0/60000 ppm 0 ppm
Relative Humidity: 0/100 % 50 %

3) TEMPERATURE

Measuring unit: °C/°F
Input: RTD Pt1000
Connection: 2/3 wires
Measuring and compensation range: -2/+52 °C (24,8/125,5 °F)
Resolution: ± 0.1 °C (0,1 °F)
Zero: ± 2°C (± 3,6 °F) 0°C
Manual temperature: 0/50°C (32/122 °F) 20°C

Instruction manual - Rev. A - 07/09

Default

DO+SET

416 mV

0/200.0 % air sat
0/20.00 ppm
0/20.00 mg/l
0/200.0 mmHg

100 %

2.0 s

10.0 s

Default

Default

°C

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B&C Electronics OD 7685.110

4) SET-POINT (Relays A-B)

* Action: ON-OFF
Set-point value: 0/20.00 PPM

Hysteresis: 0/2.00 PPM
Activation delay: 0/99.9 seconds

* Function: HI/LO (Max/Min)

5) CLEANING FUNCTION (Relays C-D)

* Action: Disable/Manual Clean/Auto+Manual Clean

Auto Clean:
Cycle repetition: 0.1/24.0 hours
* Number of cycle (N):1/10
* Charging time: 0.5/60.0 seconds
* Discharging time: 0.0-10.0 seconds

Relay C (compressor) ON for:
(Charge time+Discharge time)*(N-1)+(Charge time-2")

Relay D (valve) OFF for: charge time
Relay D (valve) ON for: discharge time

* Hold time: 0.1/20.0 minutes

Relays contacts: SPST (NO) 220 V 5 A resistive load

Default

0 PPM
0 PPM

0.0 s
LO

Default

Disable

24.0 h
4

15.0 s

3.0 s

3.0 min.

6) ANALOG OUTPUT Nr. 1

* Input channel connected to out 1: O2/°C
* Current range: 0-20/4-20 mA

* Point 1 for output 1:
Range: 0.0/40.0 PPM

Range: 0.00/20.00 PPM

Temperature: 0.0°C/50.0°C (32.0/122.0 °F)
* Point 2 for output 1:
Range: 0.0/40.0 PPM
Range: 0.00/20.00 PPM
Temperature: 0.0°C/50.0°C (32.0/122.0 °F)

Response time: 10 seconds for 98%
Isolation: 250 Vac
Rmax: 600 ohm

Default

O2
4/20 mA

0.0 PPM

0.00 PPM

0.0 °C

40.0 PPM

20.00 PPM

50.0 °C

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B&C Electronics OD 7685.110

7) ANALOG OUTPUT Nr. 2

* Input channel connected to out 2: O2/°C
* Current range: 0-20/4-20 mA

* Point 1 for output 2:
Range: 0.0/40.0 PPM

Range: 0.00/20.00 PPM

Temperature: 0.0°C/50.0°C (32.0/122.0 °F)

* Point 2 for output 2:
Range: 0.0/40.0 PPM
Range: 0.00/20.00 PPM
Temperature: 0.0°C/50.0°C (32.0/122.0 °F)

Default

O2
4/20 mA

0.0 PPM

0.00 PPM

0.0 °C

40.0 PPM

20.00 PPM

50.0 °C

Response time: 10 seconds for 98%
Isolation: 250 Vac
Rmax: 600 ohm

8) SERIAL COMMUNICATION (option 091.701)

Baud Rate: 4800 bit/s

Default

Nr. of bit: 8 bit
Nr. of stop bit: 1 bit
Parity: None
Isolated from measuring circuits
Example of data: ±20.00PPM ±50.0°C Z:-0.500mV S:100.0%
Data sent every: 0.4 seconds

9) 24 VAC POWER SUPPLY (option 091.404)

Default

Voltage: 24 Vac +/-10 % 50/60 Hz
Power: 5 VA max

10) VDC POWER SUPPLY (option 091.4143)

Default

Voltage: 9 to 36 Vdc
Power: 4 W max.
Absorption max.: 320 mA at 12 Vdc
160 mA at 24 Vdc
Isolation I/O: 1500 Vdc

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B&C Electronics OD 7685.110

11) PARAMETERS ON CONFIG BLOCK (See for *)

Free calibration (access code not required):
Keyboard Locked/Unlocked.

LCD contrast (0/7).
Main display: DO+SET/DO+TEMP
Temperature unit: °C/°F
Under access code number (0):
Measuring unit (mmHg,%air,ppm,mg/l).
Range of measure (40.0/20.00)
Autorange on/off
Digital filter response time (large): 0.5/50.0"
Digital filter response time (small): 0.5/50.0"
Input connected to out 1 (O2/°C/°F)
Range of analog output 1 (0/20 4/20mA)
Point 1 for output 1
Point 2 for output 1
Input connected to out 2 (O2/°C/°F)
Range of analog output 2 (0/20 4/20mA)
Point 1 for output 2
Point 2 for output 2
Function of relay A (HI/LO).
Function of relay B (HI/LO).
Cleaning function (Auto/Manual/Disabled)
Number of cycle for cleaning function: 1/10
Charging time: 0.5/60.0"
Discharging time: 0.0/10.0"
Holding time before restarting of normal operation: 0/60.0'
Access Number: 0/999

12) GENERAL SPECIFICATIONS

Acquisition time: 0.4 seconds approx.
Alphanumeric display: 1 line x 16 characters

Operating temperature: 0/50 °C
Humidity: 95% without condensate
Power supply: 110/220 Vac +/- 10% 50/60 Hz
Isolation: 4000 V between primary and secondary (IEC 348)
Power: 5 VA max.
Terminal block: extractable
Weight: 850 g

Default

Unlocked
4
DO+SET
°C

ppm

20.00
off

2.0"

10.0"
O2
4/20

0.00

20.00
°C (°F)
4/20

0.0

50.0
LO
LO
Disabled
4

20.0"

3.0"

3.0'
0

Default

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B&C Electronics OD 7685.110

2.3 PHYSICAL DESCRIPTION

The controller enclosure is designed for surface or panel mounting.

It consists of an anodized aluminum case built according to the standard DIN 43700, with an
aluminum panel coated with scratch-proof and non-corrosive polycarbonate membrane.

A transparent waterproof front door SZ7601 can be added to the housing, in
order to protect the unit from excessive moisture or corrosive fumes.

Signal and power cable connections are made by using two extractable terminal blocks placed in the
back of the instrument.

This makes wiring, installation and general maintenance of the probes and other devices easier.

The package is supplied complete with fixing clamps for panel-mounting.

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B&C Electronics OD 7685.110

3 OPERATING THE SYSTEM

1. LCD display

electronics

2. Mode-Display key

3. Calibration key

4. Increase key

5. Decrease key

6. Enter key

Fig. 1

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