RH-Combo-Wall-Plate-Nickel

Supported Applications

The ACI Relative Humidity Wall Plate Series with Platinum RTD Temperature Sensor is a relative humidity transmitter designed for use in commercial heating and cooling building management systems. The series supports space temperature monitoring via an optional sensor element. Documented applications include pharmaceutical facilities, hospitals, operating rooms, vivariums, clean rooms, process control environments, wash down areas, and stability chambers.

Operating Conditions & Performance

The transmitter operates within a relative humidity range of 0 to 95% RH (non-condensing) with conformally coated PCBs. The operating temperature range is -40 to 140 °F (-40 to 60 °C), and the storage temperature range extends from -40 to 149 °F (-40 to 65 °C). Relative humidity accuracy at 77°F (25°C) is specified as +/- 2% or 3% from 10 to 95%. The RH sensor type is capacitive with a hydrophobic filter, featuring a typical response time of 20 Seconds. Stability and repeatability are rated at less than 2% drift over 5 years, 0.5% RH, and 0.1% RH sensitivity.

For the Nickel RTD temperature sensor (PTC), accuracy specifications vary by temperature: +/-0.72°F (0.4°C) at 32°F (0°C); +/-0.34°F (0.17°C) at 70°F (21.1°C); and +/-1.00°F (0.56°C) at 130°F (54.4°C). The sensor follows the Din 43760 standard with a temperature coefficient of 6370 ppm/°C.

Configuration Options

The series is configured for wall mounting over a single gang junction box using a brushed stainless steel (430 Stainless Steel) plate. Electrical connections utilize screw terminal blocks that are polarity sensitive, accepting wire sizes from 16 AWG (1.31 mm²) to 26 AWG (0.129 mm²). The unit is powered by either AC or DC supply voltage depending on the output configuration:

• For 0-5 VDC output: 12 - 40 VDC / 18 - 28 VAC
• For 0-10 VDC output: 18 - 40 VDC / 18 - 28 VAC

The transmitter features integral DIP switches for field selection of the proper output signal (3-wire: 0-5 or 0-10 VDC) and supply voltage. It includes built-in test options at 0%, 50%, and 100% to verify operation, along with increment/decrement calibration DIP switches that allow field adjustment without replacing the sensing element.

Available sensor configurations include Nickel RTD (PTC), Platinum RTD, Thermistor, Balco, and various thermistor series. Optional accessories include a 3/8" Sintered Filter for RH Duct/Stainless Plate/Remote Probes and a 1" EZ Vinyl Filter Cover.

Key Product Differences

The ACI Wall Plate Series is offered with different temperature sensor technologies, including Nickel RTD (PTC), Platinum RTD, Thermistor, Balco, and specific thermistor series such as A/1.8K, A/3K, A/AN (Type III), A/CP (Type II), and others. Accuracy options for relative humidity are available at +/- 2% or +/- 3%. Output signals can be field-selected between 0-5 VDC and 0-10 VDC via integral DIP switches.

Three-point NIST Calibration Certificates are an optional feature, with default test points set at 20%, 50%, and 80% RH. The series includes a temporary plastic sensor cover for protection during wash down applications or chemical exposure.