The QFM21 duct sensors are designed for measuring relative humidity and temperature. They are powered by AC 24 V or DC 13.5.35 V and feature DC 0.10 V/ 4…20 mA signal output for relative humidity and DC 0.10 V/ 4…20 mA or T1 or LG-Ni 1000 output for temperature. The measuring accuracy is ±3 % relative humidity within the comfort range.
This manual covers the QFM21 series duct sensors used for measuring relative humidity and temperature in HVAC applications. It describes the sensor principle, performance parameters, and the various signal output options (DC 0‑10 V or 4‑20 mA).
Installation, wiring, and safety guidelines are provided, along with engineering notes on power supply, EMC considerations, and troubleshooting procedures for sensor faults. This manual is written in Japanese.
| Operating voltage | AC 24 V or DC 13.5–35 V |
|---|---|
| Signal output (humidity) | DC 0–10 V or 4–20 mA |
| Temperature measurement range (QFM2120) | -35 °C to +50 °C |
| Weight (QFM2100) | 0.18 kg |
The sensor can be powered from AC 24 V or DC 13.5 V to 35 V.
Humidity can be output as either DC 0–10 V or a 4–20 mA current loop.
Model QFM2120 measures temperature from –35 °C to +50 °C.
A QFM2100 sensor weighs approximately 0.18 kg.