GF Signet 2850 User Manual

Signet 2850 Conductivity/Resistivity Sensor Electronics

English

*3-2850.090-1*

3-2850.090-1 Rev. H 06/12 English

SAFETY PRECAUTIONS

1. Depressurize and vent system prior to installation or removal.

2. Confi rm chemical compatibility before use.

3. Do not exceed maximum temperature/pressure specifi cations.

4. Wear safety goggles or faceshield during installation/service.

5. Do not alter product construction.

6. When using chemicals or solvents, care should be taken and appropriate
eye, face, hand, body, and/or respiratory protection should be used.

Contents

1. Description

2. Specifi cations

3. In-Line Installation

4. Submersible Installation

5. Wiring 4 to 20 mA Output version

6. Wiring Digital (S3L) Output version

7. Wiring Dual Input Digital (S

8. Cell Constant Selection

9. Range Selection for 4 to 20 mA Output

10. Calibration

11. Maintenance

12. Ordering Information

1. Description

• Signet 2850 Conductivity/Resistivity Sensor Electronics provides either a two-wire 4 to 20 mA output or Digital (S3L) format.

• The 4 to 20 mA output models provide eight ranges for each electrode cell constant, plus the ability to invert each range.

• The EasyCal feature allows the devices to automatically recognize standard conductivity test solution values for simple fi eld calibration.

• The Conductivity sensor provided with integral systems will have its custom cell constant information programmed into the electronics
at the factory to provide a 1% sensor accuracy. See Section 8 for details.

3

L) Output version

2. Specifi cations

General

Compatible Electrodes: Any Signet Conductivity/

Resisitivity electrode
(2818-2823, 2839-2842)
Temperature Compensation: PT-1000 RTD (2% per °C)
Pure Water Compensation: Auto-switching when using

0.01 cell and raw conductivity

value < 0.5 S

EasyCal:
Automatic recognition of the following conductivity values:

• 146.93 S, 1408.8 S, 12856 S (@ 25 °C)
(Test solutions per ASTM D1125-95)

• 10 S, 100 S, 200 S, 500 S, 1000 S, 5000 S, 10,000 S,

50,000 S, 100,000 S (@ 25 °C)

Electrical

Power: 12 to 24 VDC (4 to 20 mA output)
5 VDC ±5% regulated, 3.0 mA

max. for Digital (S

(Reverse polarity and short circuit

protected)

Digital (S

• Accuracy: Conductivity: ±2% of reading
Temperature: ±0.5 °C

• Resolution: Conductivity: 0.1% of reading
Temperature: < 0.2 °C

• Update Rate: Single input models: < 600 ms
Dual input models: < 1.2 s

3

L) Output: Serial ASCII, TTL level 9600 bps

3

L) output

Current Output:

• Field-selectable ranges

• Factory set span:

0.01 cell (2818, 2819, 2839): 4 to 20 mA = 0 to 100 S

0.10 cell (2820, 2840): 4 to 20 mA = 0 to 1000 S

1.0 cell (2821, 2841): 4 to 20 mA = 0 to 10,000 S

10.0 cell (2822, 2842): 4 to 20 mA = 0 to 200,000 S

20.0 cell (2823): 4 to 20 mA = 0 to 400,000 S

• Max. Loop Resistance: 50  @ 12 VDC
325  @ 18 VDC
600  @ 24 VDC

• Accuracy: ±2% of output span

• Resolution: 7 A

• Update Rate: <600 ms

• Error Indication: 22 mA

Available data via Digital (S

• Raw conductivity

• Calibrated conductivity

• Calibrated temperature-compensated conductivity

• Temp. Error Indication: Open input and out-of-range

Environmental

Material: PBT
Enclosure Rating: NEMA 4X/IP65
Operating Temperature: -10 to 85 °C (14 to 185 °F)
Storage Temperature: -20 to 85 °C (-4 to 185 °F)
Relative Humidity: 0 to 95%, non-condensing
Shipping Weight: 0.75 kg (1.75 lb.)

3

L) Output:

diagnostics for temperature or
internal electronic error.

Standards and Approvals

• CE

• Manufactured under ISO 9001 and ISO 14001

China RoHS (Go to www.gfsignet.com for details)

Dimensions

2850-51, -52 Integral mount 2850-61, -62, -63 Universal mount

95 mm

3.74 in.

95 mm

3.74 in.

Conductivity Sensor Dimensions

73.66 mm
(2.9 in.)

3-2818

41.91 mm
(1.65 in.)

12.7 mm
(0.5 in.)

32.39 mm
(1.28 in.)

85 mm

3.34 in.

4.6 m (15 ft)
cable (std)

152 mm
(6 in.)

107 mm
(4.2 in.)

49.5 mm
(1.95 in.)

12.7 mm
(0.5 in.)

3-2819, 3-2820, 3-2821

¾ in. NPT

2820-x

20.3 mm
(0.8 in.)

2821-x

7.6 mm
(0.3 in.)

82 mm

3.24 in.

T1 = 50 mm (2.0 in.)
T2 = 64 mm (2.5 in.)

152 mm
(6.0 in.)

126 mm

(5.0 in.)

3-2819, 3-2820, 3-2821

Sanitary

13 mm
(0.5 in.)

73.7 mm

2.90 in.

Operating Range Chart

(0.01 Cell)

59.3 mm

2.33 in.

3-2839 3-2840

UPW @ 25°C

USP

35.8 mm

1.41 in.

(1.0 Cell)

(0.10 Cell)

2818/2819/2839

2820/2840

21.5 mm

0.85 in.

(10.0 Cell)

2821/2841

Bottled

Water

(20.0 Cell)

2822/2842

2823

41.9 mm

1.65 in.

Cooling Tower
Waste Waters

203 mm

8.0 in.

89 mm

26.8 mm

1.13 in.

3.5 in.

3-28233-2841, 3-2842

Deionization Regen. Chemicals

Alkali Cleaners, Acids/Bases

0.010 μS

0

0

1 μS

0

10 μS

.

50 μS

100 μS

.

1,000 μS 10,000 μS

50,000 μS

200,000 μS

400,000 μS 200 μS 100,000 μS 0.055 μS

0.5 μS 20 μS

2 2850 Conductivity/Resistivity Sensor Electronics

3. In-Line Installations

Most of the Conductivity/Resistivity electrodes used with the 2850
can be installed into standard 3/4 in. (NPT or ISO 7-R3/4) fi ttings.

The 2850-5X models are designed for integral systems, where
the electronics are attached directly to the sensor.

The preferred installation for in-line applications directs fl ow
straight into the electrode. This confi guration reduces the
probability of entrapped air bubbles, and provides the best
continuous sampling of the fl uid content.

If the electrode is mounted vertically in a tee, do not recess the
electrode orifi ces inside the tee. Mounting upside down may help
prevent air entrapment.

An oversized tee or fl ow cell may be helpful for inline installations.
At least 4 threads (ANSI B1.20.1) must be engaged to meet the
pressure rating as published in the specifi cations.

Use the 2850-6X models for in-line installations where the
electronics must be separated from the electrode. Conductivity
electrodes with sanitary fl ange fi ttings must be installed using this
option.

4. Tank Installations

While the 2850-5X and -6X electronics cannot be submerged, either model will
accomodate tank installation.

Select any electrode with a 5 m (15 ft) cable. The cable may be cut to length, but it
CANNOT BE EXTENDED.

The universal adapter included with 2850-6X models can be attached to the top of a
tank or mounted to a surface near the tank.

Adapt the 2850-5X models to tank installations by attaching a clamp to the conduit.

32850 Conductivity/Resistivity Sensor Electronics