Dwyer Instruments SERIES 641RM Catalog Page

1/2 NPT

1-25/32 [45.24]

SERIES 641RM

AIR VELOCITY TRANSMITTER WITH REMOTE PROBE

For Remotely Mounting Electronic Enclosure

1-5/8 [41.28] WITH LED

1-3/32 [27.78] WITHOUT LED

AIR QUALITY

The Series 641RM Air Velocity Transmitter with Remote Probe features the same

highly accurate heated mass ow sensor as the Series 641, with a remote probe construction. The units 6´ cable which connects the sensing probe with the electronic enclosure allows the enclosure to be mounted where it can be more easily accessed.

FEATURES/BENEFITS

• Ranges from 250 FPM (1.25 MPS) to 15,000 FPM (75 MPS)

• Optional bright LED display

• Easy push-button set-up

• Compact housing

• 4-20 mA output

• Digital lter for signal damping

APPLICATIONS

• Exhaust stack ow monitoring

• Air control in drying processes

• HVAC air velocity measurements

• Fan supply and exhaust tracking

• Clean room ventilation monitoring

MODEL CHART Model Description 641RM-12

641RM-12-LED

Air velocity transmitter with 6´ cable Air velocity transmitter with 6´ cable with LED display

OPTIONS To order add sufx: Description

-NIST NIST traceable calibration certicate

Example: 641RM-12-NIST

4-31/32 [126.21]

1-39/64

[40.88]

Ø5/16 [Ø7.94]

Ø13/64 [Ø5.16]

FOR A STANDARD 12˝ PROBE

SPECIFICATIONS Service: Clean air and compatible, non-

combustible gases. Accuracy: 3% FS process gas: 32 to 122°F (0 to 50°C); 4% FS process gas:

-40 to 32°F and 122 to 212°F (-40 to 0°C & 50 to 100°C). Response Time: Flow: 1.5 s to 95% of nal value (output lter set to minimum). Temperature Limits: Process: -40 to 212°F (-40 to 100°C); Ambient: 32 to 140°F (0 to 60°C). Pressure Limit: 100 psi (6.89 bar) maximum.

Humidity Limit: Non-condensing. Power Requirements: 12-35 VDC,

10-16 VAC. 1.5 A rating required on supply due to initial power surge drawn by transmitter. Output Signal: 4-20 mA, isolated 24 V source, 3 or 4-wire connection.

ACCESSORIES Model Description A-156

A-158 A-159 641-LED

Universal mounting plate, 1/2˝ female NPT Split ange mounting kit Duct mounting gland Field-upgradeable LED

43/64

[17.07]

6 FT [152.40]

14-21/64 [53.07]

31/64 [12.30]

Output Filter: Selectable 0.5–15 (seconds).

Loop Resistance: 600 Ω max. Current Consumption: 300 mA max. Electrical Connections: Screw terminal. Mounting Orientation: Unit not position

sensitive. Probe must be aligned with airow.

Weight: 13.2 oz (374.26 g). Cable Length: 6´ (1.82 m). Probe Length: 12˝ (30.48 cm) standard. Probe Diameter: 5/16˝ (0.79 cm).

OPTIONAL DISPLAY VERSION: Display: 4-1/2 digit 1/2˝ red LED. Resolution: 1 FPM, 0.01 MPS (10 FPM

@ 10,000 and 15,000 FPM ranges). Weight: 13.9 oz (394.16 g).

Air Velocity Transmitters