The RHT-WM is an HVAC temperature and humidity transmitter with a low profile suited to BMS applications, offering simple loop-powered 2-wire wiring across a -20 to 70°C, 0-100% RH range. Outputs can be configured to transmit temperature, relative humidity, or dew point, and calibration can be changed via the free SigNow application. It's also available in a duct/wall-penetrating mount version (RHT-DM) with an extended sensor probe.
The RHT-WM incorporates a highly accurate and stable sensor for measuring relative humidity and temperature. The measured values are converted into a 4 to 20mA output signal linearly related to the reading. As it's microprocessor-based, it can be fully configured using the TxConfig-USB communication interface and the SigNow application, available for Android and Windows.
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Technical Details
Sensor measurement range: Temperature -20 to 70°C (-4 to 158°F). Relative Humidity 0-100% RH (non-condensing). Dew Point -100 to 103°C (-148 to 217.4°F)
Response time: Temperature up to 30s; Humidity up to 8s (@25°C, 1 m/s airflow)
Measurement accuracy: Temperature ±0.4°C @ 25°C; Relative Humidity ±3% RH @ 25°C
Analogue outputs: 4 to 20mA or 20 to 4mA, 2-wire type, loop-powered. Resolution: 0.0008mA
Operating temperature: -20 to 70°C, 0-95% RH (electronic module)
Connections: internal terminal block, via cable glands. Materials: PA-GF housing
Degree of protection: Enclosure IP65, Sensor IP40
Configuration: SigNow software for Windows or Android via TxConfig-USB interface. Certifications: CE Mark
Frequently Asked Questions
Do I need external configuration hardware?
Yes — the TxConfig-USB interface connects the transmitter to a PC or Android device running the free SigNow application for configuration, since this transmitter doesn't have an onboard USB connector.
Can I output dew point instead of humidity?
Yes — the output can be configured to transmit temperature, relative humidity, or dew point.
Is there a duct-mount version?
Yes — the RHT-DM model has an extended sensor probe for duct or wall-penetrating mounting, with a wider -40 to 120°C range.
Industry Applications
- BMS & HVAC — low-profile wall mount design suits building management system installations.
- Data Centres — accurate humidity monitoring for equipment-sensitive spaces.
- Agriculture & Greenhouses — combined temperature and humidity readings across a wide range.