Model 657-1 Relative Humidity/Temperature Transmitter
Dual Channel Design for Simultaneous 4-20 mA Output Signals
The Series 657 Transmitters provide two 4 to 20 mA channels to produce separate output signals for both relative humidity and temperature. These devices deliver ±2% accuracy for humidity and ±1°F for temperature measurements. Stainless steel probe can be easily mounted to most ductwork using either of the two optional kits below.
Product Applications
- Cleanroom monitoring
- HVAC/building control monitoring
Models & Ordering
Specifications
- Service:
- Dry clean air.
- Range:
- Relative Humidity: 0-100%; Temperature: 32 to 212°F (0 to 100°C).
- Accuracy:
- Relative Humidity: ±2% (10-90% RH), ±3% (0-10% and 90-100% RH); Temperature: ±1°F (0.5°C).
- Enclosure Temperature Limit:
- 32 to 140°F (0 to 60°C).
- Pressure Limits:
- 1 psi (.07 bar).
- Compensated Temperature Range:
- 32 to 140°F (0 to 60°C).
- Power Requirements:
- 10-35 VDC.
- Output Signal:
- 2 channels each 4-20 mA. Loop powered on RH channel.
- Electrical Connections:
- 4 screw type terminal.
- Mounting Orientation:
- Mount in any position.
- Probe:
- 5/16" x 10" (0.8 x 25.4 cm) stainless steel.
- Weight:
- 5.5 oz (156 g).
Features
- Polymer film humidity and thin film RTD temperature sensors offer highly reliable and stable measurements
- Remote mount housing offers installation flexibility (657-1)
- Rugged die-cast aluminum housing is great for industrial applications (657C-1)
Accessories
Model Number | Description | Usually Ships* | Price | Order | |
---|---|---|---|---|---|
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A-158 | Split flange. | Same Day | $14.75 | Order |
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A-159 | Mounting gland with 1/2" male NPT. | Same Day | $29.75 | Order |
Drawings
Questions
- Question
- I'm looking for a dual temp. and humidity gauge for an 8" duct. I'm wanting to remote read the temp and humidity on the incoming and outgoing air to an ERV unit. The RHP-3M11-LCD was recommended to me, however, it is a direct read. What would be the correct instrument to remote read the temperature and humidity from a distance of 8 feet. The 8" duct is in the attic and I want to read the result in the down-stair hall. I don't want to record nor program the unit, just read the performance.
- Answer
- The sensor recommended would be the best option we have for sensing temperature and relative humidity for your application. We do not have any options with a remote display that could stretch as far as you are asking, nor are there any on the market to my knowledge. In every case, you would need to utilize a process output, in this case 4-20 mA, to transmit the readings to a remote display(s) which would accept the process signal(s). If you are just looking for a remote readout to go with the RHP sensor with no control functionality, then you could look at one of our panel meters, possibly the SPPM, DPMA, DPMW, or DPMP & DPML series panel meters. For assistance selecting an appropriate panel meter, please contact our technical support group at 219-879-8000.
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