RH+T Wet and Dry Bulb Controller

RHC201 is a relative-humidity (RH) controller that uses wet and dry bulb temperatures to measure and display RH. It receives two 4 - 20 mA or RTD inputs for wet and dry bulb temperatures within the range of -20 to 100 °C. A large two-color LED dual-display on the front of the RH controller indicates calculated RH in the upper display and in the lower either of the setpoint, Tdry, Twet or the difference between the two bulb temperatures. 6 additional LEDs indicate the status of each relay and the parameter in the lower display. Operators program up to 2 setpoints easily via membrane buttons on the front of RHC201. The controller has an accuracy of ± 2 RH with a Class A Pt100 RTD and ± 0.5 RH for linear input. RHC201’s electromagnetic relays trigger humidification (heating), dehumidification (cooling), or any of six alarms - full-scale high and low, deviation high and low, inband and outband. Relays can be assigned to RH or Tdry. It transmits two isolated output signals to other devices such as a Programmable Logic Controller (PLC) or Solid-State Relay (SSR). Signal isolation protects your devices and machines downstream of our instruments from damaging fluctuations in the input signal. RHC201 is conventionally an ON-OFF controller that outputs a discrete signal, but can also be used in Time-Proportioning Mode which turns the actuator on and off for periods proportional to the desired control effort, to emulate a continuous actuator that can generate a control effort between 0 and 100%. By including input terminals in the excitation loop, RHC201 provides a 24 V DC power supply for two-wire 4-20 transmitters.