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Vaisala HMP228 User Manual

Page 35

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HMP228

M210282en-A

Operating Manual

29

If you want to see how the sensor stabilizes to the reference
temperature, enter c instead of the first reference:

T : 0.90 Ref1 ? c
T : 0.55 Ref1 ? c
T : 0.55 Ref1 ? 0.0
Press any key when ready...

Change the temperature and again check the transmitter against the
reference.

Check that the reading corresponds with the reading of the reference
instrument. If not, adjust the second point.

Press any key, enter the second point value and press .

T : 20.0 Ref2 ? yy.y

The stabilization of the sensor can be monitored well by entering c
instead of the reference value.

4.6.2.2

Using display/keypad commands

Leave the reference instrument and the transmitter for at least 4 hours
in the same space so that their temperatures have time to equalize.
Remove the filter cap prior to calibration.

Check the transmitter against the reference.

Select Cali in the main menu and then T cal; select two-point
calibration T 2 point cal. Change the first point reading with the
arrow keys and press ENT.

Change the temperature and again check the transmitter against the
reference.

Check that the reading corresponds with the reading of the reference
instrument. If not, adjust the second point.

If necessary, change the second point reading with the arrow keys and
press ENT.

4.6.2.3

Using LED commands

Leave the reference instrument and the transmitter for at least 4 hours
in the same space so that their temperatures have time to equalize.
Remove the filter cap prior to calibration.

Check the transmitter against the reference.

Connect an ammeter/voltmeter to the analogue outputs (connector
X2). Give command ¡¡l¡. At the first calibration point the LED
on the left flashes; adjust the first point (offset) with the arrow
switches to the same reading with the reference and press ENT
switch.

Change the temperature and again check the transmitter against the
reference.