Manual

E-M-HF5-V1_25

Rotronic AG

Bassersdorf, Switzerland

Document code

Unit

HygroFlex HF5 Humidity Temperature

Transmitters: User Guide

Instruction Manual

Document Type

Page

12 of 30

Document title

5 Mechanical installation

5.1 General guidelines

Relative humidity is extremely dependent on temperature. Proper measurement of relative humidity requires

that the probe and its sensors be at exactly the temperature of the environment to be measured. Because of

this, the location where you choose to install the probe can have a significant effect on the performance of the

instrument. The following guidelines should guarantee good instrument performance:

a) Select a representative location: install the probe where humidity, temperature and pressure

conditions are representative of the environment to be measured.

b) Provide good air movement at the probe: air velocity of at least 200 ft/ minute (1 meter/second)

facilitates adaptation of the probe to changing temperature.

c) Avoid the following: (1) Close proximity of the probe to a heating element, a cooling coil, a cold or

hot wall, direct exposure to sun rays, etc. (2) Close proximity of the probe to a steam injector,

humidifier, direct exposure to precipitation, etc. (3) Unstable pressure conditions resulting from

excessive air turbulence.

d) Immerse as much of the probe as possible in the environment to be measured.

e) Prevent the accumulation of condensation water at the level of the sensor leads. Install the

probe so that the probe tip is looking downward. If this is not possible, install the probe horizontally.

5.2 HF5 enclosure

The HF5 enclosure consists of a base and a cover held together with 4 screws. To open the enclosure, use a

metric 2.5 mm hex key. Prior to re-assembling the enclosure, verify that the red seal is sitting properly in its

groove on the base.