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Series CRF2 Capacitive Level Transmitter

Specifications - Installation and Operating Instructions

Bulletin L-36

The 

Series CRF2 Capacitive Level Transmitter

 is a level transmitter providing a two-

wire 4 to 20 mA output to indicate level of liquids, powders and bulk materials. State of 

the art sensing technology in the CRF2, using impulse RF admittance measurement 

provides excellent accuracy and stability. The CRF2 senses capacitance changes 

resulting from the height of the material in the tank between the probe and the tank 

wall. In non-metallic tanks or tanks that do not have the wall parallel to the probe a 

ground reference must be used.

The  CRF2  comes  with  either  a  rigid  or  flexible  probe  depending  on  application 

installation need and probe length required. Featured in the CRF2 is easy push button 

calibration of zero and span. Custom order the CRF2 to any length probe that you 

need for your application. FEP covered probe is ideal for use with corrosive media.

SPECIFICATIONS

Service:

 Liquids, powders, and bulk materials compatible with wetted materials.

Wetted Materials:

 Standard: rod/cable: FEP; connection: 316 SS. Ground Option: 

rod/cable and connection: 316 SS; cable spacers: PVC. Flange Option: material of 

flange.

Capacitance Range:

 0 to 2000 pF.

Sensitivity:

 0.15 pF.

Minimum Span:

 8 pF.

Accuracy:

 ±0.5 pF or ±0.25% of span, whichever is greater.

Repeatability:

 ±0.25 pF or ±0.1% of span, whichever is greater.

Temperature Limits:

 Ambient: -40 to 185°F (-40 to 85°C); Process: -40 to 250°F 

(-40 to 121°C).

Pressure Limit:

 100 psi (6.9 bar).

Power Requirements:

 12 to 35 VDC.

Output Signal:

 4 to 20 mA or 20 to 4 mA, 2 wire.

Response Time:

 0.5 seconds.

Electrical Connection:

 Screw terminal.

Conduit Connection:

 1/2˝ NPT female. 

Process Connection:

 Standard: 3/4˝ NPT male. Optional: See model chart. 

Enclosure Rating:

 NEMA 4X (IP66) weather-tight/corrosion resistant.

Spark/Static Protection:

 106 Ω dissipation resistance with spark gap. Surge 

current to 100A max.

Calibration:

 Zero, Span, 4 mA, 20 mA.

Mounting Orientation:

 Vertical. 

Weight:

 6 ft rod type: 3.6 lb (1.63 kg).

2X 1/2 FEMALE

NPT CONDUIT

CONNECTION

3-19/32

[91.28]

4-1/2

[114.30]

3/4 MALE

NPT PROCESS

CONNECTION

9/16

[14.29]

4-3/16

[106.36]

2X 3/4 [19.05]

CLEARANCE FOR

COVER REMOVAL

“L”

2X 1/2 FEMALE NPT

CONDUIT CONNECTION

4-7/16

[112.7]

2-3/8

[60.3]

MOUNTING

BRACKET

1-3/8

[34.9]

2-3/4

[70.0]

3-1/4

[82.6]

3-5/32

[80.2]

6

[152.4]

3/4 MALE NPT

PROCESS CONNECTION

“L”

120

[3048]

Remote Mount Housing

MERCOID 

P.O. BOX 373 • MICHIGAN CITY, INDIANA 46360, U.S.A.

Phone: 219/879-8000
Fax: 219/872-9057

www.dwyer-inst.com
e-mail: [email protected]

A DIVISION OF

DWYER INSTRUMENTS, INC.

By Dwyer

Summary of Contents for CRF2 Series

Page 1: ...cers PVC Flange Option material of flange Capacitance Range 0 to 2000 pF Sensitivity 0 15 pF Minimum Span 8 pF Accuracy 0 5 pF or 0 25 of span whichever is greater Repeatability 0 25 pF or 0 1 of span whichever is greater Temperature Limits Ambient 40 to 185 F 40 to 85 C Process 40 to 250 F 40 to 121 C Pressure Limit 100 psi 6 9 bar Power Requirements 12 to 35 VDC Output Signal 4 to 20 mA or 20 to...

Page 2: ...tant for air is very close to 1 0 and usually assumed to be exactly 1 0 Capacitive level sensors determine the level of material by changes in probe capacitance resulting from the movement of dielectric materials between the probe and the reference ground electrode such as a tank wall Since measuring very small capacitance changes less than 1 pF can be problematic in industrial environments capaci...

Page 3: ...r and tighten the cable gland to protect and seal the connections Electrical Connection See Figure 3 NOTE Installation must be made in accordance with local codes and regulations When fishing wire through the conduit connection do not allow the wire to touch or press on components on the boards Damage to the circuitry may result Make sure that the wire is routed so it will not interfere with the c...

Page 4: ...roximately 4 00 mA Adjust the 4 mA set point by pressing the Zero 4 mA button to decrease the current and the Span 20 mA button to increase the current When complete press both the Zero 4 mA and Span 20 mA buttons simultaneously to exit the calibration mode To calibrate the 20 mA calibration point double click the Span 20 mA button by pressing it twice within 1 5 seconds The milliammeter will indi...

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