TESTO 6681 Instruction Manual page 60

testo 6681 Ethernet
60
2 Expose the humidity probe (4) of the testo 6681 and the reference
probe (3) to the same reference conditions (e.g. in the humidity
generator) and allow climatic conditions to equalize.
3 Switch on the testo 400/650. The two-part display of the handheld
instrument will show the values of the transmitter on the left, and
the values of the reference probe on the right. The humidity and
temperature values are adjusted to the reference probe using the
Probe > Probe Adjustment menu item on the testo 400/650.
The 1-point adjustment is performed for both the humidity and the
temperature.
4 Disconnect the adapter (2) from the service interface (5).
5 Close the service flap.
1.3.5.3 2-point adjustment
With the 2-point adjustment, the parameter is adjusted to the reference value
at the two standard adjustment points 11.3 % RH and 75.3 % RH or 20 % RH
and 80 % RH. The reference conditions are created either by using Testo
humidity adjustment set (order no. 0554 0660, only for adjustment points 20
%RH and 80 %RH) or in the humidity generator.
Deviation
In the 2-point adjustment, the deviations between the reading and the
nominal value are minimized across the entire measuring range. The 2-point
adjustment is therefore recommended for large working ranges, e.g. in drying
processes.
The 2-point adjustment can be performed
via P2A software (see volume 2, chapter 3, page 142) or

using the adjustment keys under the service flap, see description of

how to proceed below.
The 2-point adjustment for the adjustment points 20 %RH and 80 %RH is
carried out via the user menu.
- 1.3 Commissioning
after
before