B&C Electronics ST 6115 INSTRUCTION MANUAL

CERT. N. 9115 BCEL

INSTRUCTION MANUAL

UNI EN ISO 9001:2000

ST 6115

OPTICAL DISSOLVED OXYGEN

4-20 mA CURRENT LOOP

AUTOCLEAN

Option

S/N

REP N°

Range: 0/20 PPM

Power: 9/36 Vdc

Firmware: R 1.0x

Cod. 280166115 – Rev. A BC3531-A - Rev.01

B&C Electronics Srl - Via per Villanova 3 - 20040 Carnate (Mi) - Italy - P.IVA 00729030965
Tel [phone] - Fax [phone] – [e-mail] - www.bc-electronics.it

B&C Electronics ST 6115

Index

1 DESCRIPTION..................................................................................................................................2

1.1 Principle of operation ...............................................................................................................2

1.2 Accessories ...............................................................................................................................2

2 TECHNICAL SPECIFICATIONS ....................................................................................................3

3 INSTALLATION ..............................................................................................................................5

3.1 How to use the auto clean sensor assembling...........................................................................5

3.2 How to use the probe without the cleaner ................................................................................5

3.3 Connections ..............................................................................................................................6

3.4 Connection to BC 7635 or BC 7335 controllers......................................................................6

4 CALIBRATION.................................................................................................................................7

5 MAINTENANCE ..............................................................................................................................7

6 RESET ...............................................................................................................................................8

WARRANTY CERTIFICATE...............................................................................................................11

REPAIRS................................................................................................................................................11

TECHNICAL SUPPORT .......................................................................................................................12

Instruction manual - Rev. A – 02/09

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B&C Electronics ST 6115

1 DESCRIPTION

This unique submersible probe has been designed to measure dissolved oxygen based on fluorescent
technology.

The measuring system consists of:

- optical device complete with a layer of fluorescent material,

- electronic circuit with an exciting beam and fluorescence detection,

- built-in 2-wire 4/20 mA transmitter,

- digital inputs for calibration and configuration procedures,

- nozzle for the sensor autoclean by external pressure air.

The automatic temperature compensation is done internally by means of a built-in sensor.

Thanks to its 4/20 mA isolated output, the probe can be directly connected to a PLC or data logger,
without using amplifiers or other devices.

The probe can be connected to B&C Electronics controller BC 7635 or BC 7335, which provide the
power to the probe, the measuring readout, 2 set-points and an alarm.
The digital input of those controllers may keep in hold the functions during the autoclean cycle.

The most common applications of this probe include: water quality monitoring, municipal and
industrial water treatment and aquaculture.

1.1 PRINCIPLE OF OPERATION

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, and a good sensitivity in a low oxygen
concentration.

1.2 ACCESSORIES

The installation of the probe needs few accessories to be selected among the following:

0012.450043 Extension pipe adapter.

0012.000624 Swivel mounting (it includes the 0012.450043 adapter)

0012.440040 33 m PVC tubing for pressure air.

Instruction manual - Rev. A – 02/09

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B&C Electronics ST 6115

2 TECHNICAL SPECIFICATIONS

CURRENT LOOP

Current loop proportional to the d.oxygen: 4/20 mA

SENSOR TYPE

Optical DO
Sensing element: replaceable

SCALE

Measuring unit: ppm
Scale: 0.00/20.00 ppm

Resolution: 0.01 ppm

Drift: < 1% year
Response time: 95%< 60s

Automatic temperature compensation:

- internal table
(salinity 0ppm chloride)

Filter software
Response time to 90 % small signal: 120 seconds
Response time to 90% large signal: 40 seconds

TEMPERATURE

Compensation range: 0.0/50.0°C
Temperature coefficient: internal table

POWER SUPPLY

Voltage: 9/36 Vdc
Current: 22 mA max

RTD Pt100 built in sensor

Instruction manual - Rev. A – 02/09

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