Vaisala HMM212 - Manual (Page 13)

Chapter 2 __________________________________________________________ Product Overview
CHAPTER 2
PRODUCT OVERVIEW
This chapter introduces the features and advantages of the Vaisala
HUMICAP
®
Humidity and Temperature Module HMM212.
Introduction to HMM212
The HMM212 modules are designed especially for relative humidity
measurements in environmental chamber applications with high
temperature and humidity levels.
The HMM212 module is a microprocessor-based instrument with
temperature compensation in RH measurements. The module includes
separate 4 ... 20 mA loop powered RH and T channels. The humidity
probe length is an order-specified option. Furthermore, the customer can
also order the module with:
- a suitable cable length (0.65 m, 1.50 m or 3.0 m)
- a temperature loop current scaled for that particular application
(0 ... 100 °C, -20 ... +120 °C, -20 ... +180 °C, -40 ... +180 °C or
-70 ... +180 °C)
The HMM212 modules are connected to process control systems with
screw terminals. These versatile modules incorporate the
HUMICAP
®
180R humidity sensor, which uses an operating principle
based on changes in the capacitance of a thin polymer film as it absorbs
water molecules. The HMM212 modules measure temperature with the
reliable Pt 1000 sensor.
VAISALA _______________________________________________________________________ 13