Ambient Air; Level In The Control Container; Checking The Humidity And Temperature Sensor - testo 105679 Bedienungsanleitung

The control and adjustment set must be kept at a
constant temperature (20 to +30°C) for approx. 12
hours before a
probe screwed in a container is 15 minutes
for the control.
(testo 177-H1 three hours) is recommended
during adjustment. Disturbing influences
from outside (direct heat, air draught etc.) should
be eliminated.
Depending on the humidity content of the ambient air
• the salt solutions take in water from the ambient air.
Salt crystals dissolve after a while (typical of LiCl
solution). A salt solution can be pushed through the
diaphragm in the inner part of the control container.
This does not affect the functioning of the container
as long as undissolved salt crystals are present in
the salt solution.
• water evaporates from the salt solutions - salt crys-
tals are eliminated (typical for NaCl solution).
hygrotest 0554 0645
75.3%
12% t = 20°C/68°F
NaCl
Recognising the optimum level
(t=25°C/77°F)
0554.0637
The levels in the control containers may deviate from
the ideal level on account of ambient conditions.
max
There is a min/max mark on the containers which can
be easily checked. The liquid must be between these
marks. The salt should be covered by the liquid.
min
00000
8
Handling

Ambient air

control or adjustment.
The minimum adjustment time for a
An adjustment time of at least one hour

Level in the control container

Checking the humidity and temperature sensor

Optical judgement
The humidity probe should be checked as to whether
it is in perfect condition:
1. Checking for dirt
Ensure that there is no conductive dirt between the
sensors.
2. Contact of the sensors
Ensure that the sensors are fitted securely and that
the pins guarantee contact (no break).
3. Humidity sensor
Check the condition of the sensor surface i.e. if there
are any scratches, dirt, fingerprints or if the humidity
sensor is broken etc.
Handling
9