This document is a user's guide for the HMP230 Series transmitters, providing information on product description, considerations when measuring humidity, installation, commissioning, and connection to a PC.
The HMP230 series are microprocessor‑based transmitters that measure relative humidity and temperature and can calculate dewpoint, absolute humidity, mixing ratio, wet‑bulb temperature and enthalpy. They use a HUMICAP® humidity sensor and a Pt100 temperature sensor, and are available in several models (HMP231, HMP233, HMP234, HMP235, HMP237, HMP238) covering a wide temperature range.
The manual covers product description, installation, electrical connections, commissioning, calibration procedures, maintenance, technical data, spare parts, wiring diagrams and warranty information. It also details optional accessories such as different power supplies, display covers, filters and cable lengths.
| Humidity measuring range | 0–100 %RH |
|---|---|
| Temperature sensor | Pt100 |
| Temperature measurement range | -40 °C to +180 °C (for HMP234, HMP235, HMP237, HMP238) |
| Power supply options | 24 VDC (standard), 24 VAC, 115/230 VAC |
| Analogue outputs | Two outputs, selectable 0–20 mA or 0–10 V |
It can be connected via RS‑232C (standard), RS‑485/422, or a current‑loop module.
Standard 24 VDC, optional 24 VAC, and 115/230 VAC are available.