ACI A/RH3-20K-O : Outside Air Relative Humidity Sensor, 3% Accuracy, RH Outputs: 0-5, 0-10 VDC & 4-20mA (Default), 20K Ohm Thermistor, Plastic Outdoor Enclosure (Euro), Made in USA
The ACI Relative Humidity with Thermistor Outside Air Series is a humidity transmitter designed for outdoor air monitoring and various applications. Here are the key features and information:
- Sensing Element: The transmitter utilizes a thermoset polymer capacitive sensing element with a factory-applied hygroscopic filter. The filter enhances resistance to moisture, dust, and chemicals, ensuring long-term reliability.
- Output Signal: The transmitter provides a proportional analog current or voltage output signal, allowing for compatibility with different systems.
- DIP Switches: Integral DIP switches are included in the transmitter for easy field selection of the output signal and supply voltage, enabling customization to meet specific application requirements.
- Test Options: The unit incorporates 0%, 50%, and 100% test options, facilitating verification of proper functioning and wiring of the transmitter.
- Field Calibration: The transmitter supports field calibration using increment and decrement calibration DIP switches, eliminating the need for sensor element replacement.
- Enclosure: The Outside Air configurations come with a weatherproof Euro style enclosure featuring a gasketed cover. The circuit boards are conformally coated for added resistance to moisture and chemicals.
- Applications: The transmitter is suitable for monitoring outdoor air humidity, economizer control, and performing psychrometric calculations such as Enthalpy and Dew point. It can also be used in wash-down applications where resistance to moisture is crucial.
Specifications
| RH Supply Voltage (Reverse Polarity Protected): | 4-20 mA: 250 Ohm Load: 15 - 40 VDC / 18 - 28 VAC | 500 Ohm Load: 18 - 40 VDC / 18 - 28 VAC 0-5 VDC: 12 - 40 VDC / 18 - 28 VAC | 0-10 VDC: 18 - 40 VDC / 18 - 28 VAC |
| RH Output Signal: | 2-wire: 4 - 20 mA (Factory Default) | 3-wire: 0-5 or 0-10 VDC and 4 - 20 mA (Field Selectable) |
| RH Measurement Range: | 0-100% |
| Operating RH Range: | 0 to 95% RH, non-condensing |
| RH Stability | Repeatability | Sensitivity: | Less than 2% drift / 5 years | 0.5% RH | 0.1% RH |
| Nominal Thermistor Resistive Output @ 77°F (25°C) (Lead Wire Colors): | 20KΩ(Brown/Blue) |
Datasheets
 | ACI Outside Air Relative Humidity and Temp Data Sheet |
| ACI Outdoor Relative Humidity and Temp Installation |
- Sensor Type:
- Outside Air
- Humidity Element:
- 3%
- Humidity Ouput:
- 4-20 mA, 0-5 VDC, or 0-10 VDC
- Temperature Element:
- 20K
- CO2 Element:
- None
- Display:
- No Display
- Enclosure:
- Plastic Box Enclosure
