Manual

Chapter 2 __________________________________________________________ Product Overview
CHAPTER 2
PRODUCT OVERVIEW
This chapter introduces the features and advantages of the Vaisala
HUMICAP
®
Humidity and Temperature Module HMM211.
Introduction to HMM211
The HMM211 modules are designed especially for relative humidity
measurements in environmental chamber applications with high
temperature and humidity levels. They also measure temperature and
calculate the dewpoint temperature.
The HMM211 has actually three different module options to choose
from:
- Humidity and temperature module: with a standard humidity and
temperature sensor head
- Dewpoint module: with a warmed sensor head incorporating a
composite RH and T sensor
- Humidity and temperature module with two sensor heads: with a
warmed humidity sensor head incorporating a composite sensor, and
an additional temperature sensor head for ambient temperature
measurement
The HMM211 is a three wire module with four analog output options: 0
... 1 V, 0 ... 5 V, 0 ... 10 V, and 0 ... 20 mA. The module can be ordered
with the output option already selected. Other options include the length
of the humidity probe, the sensor protection and an additional
temperature probe. Furthermore, you can also order the module with a
suitable cable length (0.65 m, 1.50 m, or 3.0 m) and a temperature
measurement range best suited for that particular application (0 ... 100
°C, -20 ... +120 °C, -20 ... +180 °C, -40 ... +180 °C or
-70 ... +180 °C).
Output parameters can also be selected from various options according to
the module type. The output parameters for the RH and T module are
relative humidity and temperature. For the RH and T module with two
sensor heads, the parameters also include relative humidity and
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