HMP228 is an oil moisture and temperature transmitter for oil applications, such as paper machine lubrication oil and transformer oil.
The HMP228 is a microprocessor‑based transmitter that measures moisture in oil as water activity (aw) and also provides accurate temperature measurement. It uses a capacitive thin‑film sensor and offers two analogue outputs, with optional serial communication via RS‑232C, RS‑485/422, or a current‑loop module.
This guide covers product description, installation, commissioning, calibration procedures, analogue output configuration, power‑supply options, cable selections, and detailed appendices for serial commands, connectors, and wiring. It also includes technical data, safety information, and spare‑part lists.
| Power supply voltage | 24 VDC standard, optional 24 VAC, 115/230 VAC |
|---|---|
| Analogue outputs | 2 |
| Sensor type | Capacitive thin‑film sensor |
| Sensor cable length options | 2 m, 5 m, or 10 m |
The transmitter provides two analogue outputs.
Standard 24 VDC, with optional 24 VAC or 115/230 VAC supplies.
Via the RS‑232C interface, an RS‑485/422 module, or a current‑loop module.