The RHT-WM Relative Humidity and Temperature Transmitter converts these two physical parameters into two industry standard, isolated, highly stable and interference free 4 to 20 milliamp signals.
The sensors are mounted on a probe tip (which can be easily be replaced by adding a replacement PCB module to your order, see below for details) and are protected by a filter cover. See associated products below to view our range of filter covers for more arduous applications.
Both outputs are two wire transmitter loops, requiring a 24Vdc (nominal) supply in both loops.
The same pair of wires that supply power to the circuitry then carry the signal to the measuring device. The two outputs would normally be used as inputs to PLCs, controllers, digital indicators, or SCADA or telemetry systems.
Dimensions & Mounting
- General Specification:
- Loop powered 4 to 20 mA or 20 to 4 mA outputs. Wall Mount also available with 0 to 10 V output:
- Power supply: 12 to 30 VDC (4 to 20 mA output)
- Channel isolation: the 4 to 20 mA outputs are isolated from each other.
- Cable entry: compress fitting PG7.
- Operating limits:
- Sensor and probe (RHT-DM): -20 to 80 °C, 0% to 100% RH.
- Electronic circuit: -10 to 65 °C, 0% to 95% RH.
- Humidity measurement:
- Accuracy: ±1.5% RH @ 25 °C, from 20% to 80% RH.
- Repeatability: ±1% RH.
- Hysteresis: ±1% RH.
- Span: any value between 0% and 100% RH or -100 to 103 °C for dew point.
- Temperature measurement:
- Accuracy: ±0.5 °C @ 25 °C. Maximum ±2 °C from -40 to 80 °C.
- Repeatability: ±0.1 °C.
- Span: between -40 and 120 °C.
- Dimensions: 70 × 60 × 33 mm.
Enclosure: wall-mounting grey ABS, Dimensions: 70x60x33mm Connections
Note that each independent transmitter (RH and temperature) needs only a two-wire connection to a power source (12Vdc to 30Vdc). The 4-20mA measuring signal flows through the same two wires taking the signal to the measuring device. The power cable passes through the cable gland and is attached to the screw connector according to the instructions on the inner side of the box cover.
The maximum LOAD resistance plus the wires resistance can be calculated as: LOAD = (Vdc -12)/0.02 ohms (where Vdc is the voltage of the power supply).Options
Options coloured green
are normally held in UK stock for immediete dispatch.
The standard outputs from the both the temperature and humidity transmitter loops is 4-20mA. An optional variant gives 0-10Vdc output on both loops, just click the radio button to select this cost option.
The RHT-WM is factory calibrated to give 4-20mA for 0-100 C and 0-100% RH and upscale sensor burnout. This can easily be reprogrammed using the TxConfig adaptor and Windows software
available below, or select the "custom range" radio button and email us with your exact requirements and we will program the device for you.Associated productsClick here to view replacement RHT sensor PCB modules.Click here to view Sintered Bronze Filter tip's.Click here to view Teflon (PE) Sintered Filter tip's.Click here to view the TxConfig Configuration Software and Adapter Cable. Downloads