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

Shipping Information

All shipping times are dependent on product availability at time of shipment.

Although we make every effort to ensure a continuous supply of our products, occasional circumstances may force us to temporarily run out of a product, or have shipping delays. Should this occur, customers will be notified soon after placement of any orders for such products and, if applicable, items will be put on backorder. For orders requiring expedited shipment, our customer service team can be contacted to confirm product availability

COVID-19 Update: Due to high customer demand, lead time on some products may be up to two weeks. While this is a developing health situation, we are working continuously to take the necessary measures to ensure that the products you need are available with minimal interruption.

Model	Description	Usually Ships*	Price	Order
657-1 Ships: Same Day Price: $306.00	Relative humidity/temperature transmitter.	Same Day*	$306.00	Order

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
	A-158	Split flange.	Same Day	$14.25	Order
	A-159	Mounting gland with 1/2" male NPT.	Same Day	$29.00	Order

Product Literature

Manuals

Instruction Manual

Catalog Pages

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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