The Model 657-1 Transmitter provides two 4-20 mA channels to produce separate output signals for both relative humidity and temperature. This inexpensive device delivers ±2% accuracy for humidity and ±3% for temperature measurements. The sensor employed in the 657-1 features a state-of-the-art integrated polymer film humidity sensor and a thin-film platinum temperature sensor to assure high reliability and rock-solid stability over years of continuous service. Stainless steel probe measures 5/16" x 10" (0.8 x 24.4 cm) and can be easily mounted to most ductwork using either of the two optional kits.

SPECIFICATIONS
Service: Humidity & temperature detection in 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).
Temperature Limits: 32 to 158°F (0 to 70°C).
Pressure Limits: 1 psi max.
Compensated Temperature Range: 32 to 158°F (0 to 70°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).

ACCESSORIES -- See "Ordering" page

A-158 - Split Flange Mounting Kit.
A-159 - Duct Mounting Gland.