A wall-mounted humidity and temperature sensor with a dual LCD that shows temperature and relative humidity at the site, so staff can read the values without any other display. It outputs 4–20 mA or 0–10 VDC for HVAC systems, environmental monitoring and process control.
Why measure humidity and temperature
Temperature and humidity control in industrial areas, cleanrooms and storage spaces directly affects yield and equipment life. Mechanical hygrometers have limited accuracy and respond slowly. An electronic sensor with a capacitive or resistive element outputs a digital or analogue signal that a control system can use in real time. The HT3C21 uses a CMOS polymer capacitive humidity sensor, with good long-term stability and linearity.
Core specifications
| Item | Specification |
|---|---|
| Model | HT3C21 |
| Sensing technology | CMOS polymer capacitive humidity sensor |
| Display | Dual LCD (temperature and relative humidity) |
| Humidity range | 0 to 100 %RH, non-condensing |
| Humidity accuracy | ±2% (10–90% RH) or ±3% (standard version) |
| Temperature range | Depends on the model configuration; ask us for the range of the model you need |
| Output signal | 4–20 mA or 0–10 VDC (selectable) |
| Mounting | Wall mounted |
| Power | 24 VAC/DC (depends on model) |
| Used for | HVAC systems, environmental monitoring, process control |
Selecting a configuration
The Honeywell HT series comes in several configurations. When choosing, check:
| Option | Description | When it matters |
|---|---|---|
| Output type | 4–20 mA / 0–5 VDC / 0–10 VDC | Choose by the input of your controller |
| Accuracy class | ±2% (high accuracy) / ±3% (standard) | Semiconductor and pharmaceutical work needs high accuracy |
| Temperature output | With or without an active temperature output | Needed if you must monitor temperature as well |
| LCD display | With or without a local display | Needed if you want to read values on site |
Installation notes
Install the sensor where the airflow is representative, away from heat sources, air outlets and dead corners. For wall mounting, we suggest a height of 1.2–1.5 m above the floor. Where the humidity stays high for a long time, choose a condensation-resistant model.
Before you ask for a quote
Please have ready: (1) the measuring range, temperature and humidity; (2) the accuracy you need; (3) the output signal, current or voltage; (4) whether you need the LCD; (5) where it will be installed (indoor, outdoor or hazardous area).
Request a quote
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