ACI A/RH3-O-4X : Outside Air Relative Humidity Sensor, 3% Accuracy, RH Outputs: 0-5, 0-10 VDC & 4-20mA (Default), NEMA 3R Outdoor Enclosure, Made in USA
The ACI Relative Humidity Outside Air transmitter is designed for monitoring and controlling humidity levels in outdoor environments. This transmitter utilizes a thermoset polymer capacitive sensing element with a factory-applied hydrophobic filter to deliver accurate humidity measurements. The hydrophobic filter enhances the transmitter's resistance to moisture, dust, and chemicals, ensuring greater long-term reliability in challenging outdoor conditions.
The RH Outside Air transmitter offers a proportional analog current or voltage output signal, providing flexibility in integrating with various systems. Integral DIP switches are included, enabling field selection of the appropriate output signal and supply voltage to meet the specific requirements of the application.
To verify proper functionality and wiring, each unit contains 0%, 50%, and 100% test options. These options allow for testing and validation of the transmitter's performance and correct installation.
Field calibration can be performed using the increment and decrement calibration DIP switches, eliminating the need to replace the sensing element. This calibration method offers increased flexibility and maintains long-term reliability without requiring sensor replacement.
The Outside Air configurations of the ACI Relative Humidity transmitter feature a weatherproof Euro-style enclosure with a gasketed cover. This design provides protection against outdoor elements and ensures reliable operation in harsh weather conditions. Additionally, the circuit boards of the transmitter are conformally coated, further increasing their resistance to moisture and chemicals.
The ACI Relative Humidity Outside Air transmitter finds applications in various settings, including:
- Monitor Outdoor Air Humidity: These transmitters are used to monitor and measure humidity levels in outdoor environments, providing valuable data for weather monitoring, HVAC systems, and environmental control.
- Economizer Control: In HVAC systems with economizers, the RH Outside Air transmitters help optimize energy efficiency by providing accurate humidity measurements for effective economizer control.
- Psychrometric Calculations: The transmitter can be utilized for psychrometric calculations, such as enthalpy and dew point calculations, which are important in HVAC systems and energy management.
- Wash-Down Applications: The transmitters' weatherproof enclosure and moisture-resistant features make them suitable for wash-down applications where frequent cleaning or exposure to moisture and chemicals is required.
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 |
Datasheets
 | ACI RH Outside Air Relative Humidity Data Sheet |
| ACI Outdoor Air Relative Humidity Installation |
- Sensor Type:
- Outside Air
- Humidity Element:
- 3%
- Humidity Ouput:
- 4-20 mA, 0-5 VDC, or 0-10 VDC
- Temperature Element:
- None
- CO2 Element:
- None
- Display:
- No Display
- Enclosure:
- NEMA 4X Enclosure
