3 using led commands, 2 two point calibration procedure, 1 using serial commands – Vaisala HMP260 User Manual
Page 46
HMP260 SERIES
Operating Manual
HMP260-U017en-1.5
40
1997-11-25
6.1.1.3
Using LED commands
Disconnect the security lock jumper!
•
Make sure that the sensors of the transmitter and the reference in-
strument are close to each other. Allow enough time for the sensor
heads to stabilize to the measurement conditions
•
Connect an ammeter/voltmeter to the analogue outputs (connector
X2); if the outputs are already connected e.g. to a process computer
and you do not want to disconnect them, the current output can be
measured at separate test points located next to connector X15 (see
Chapter 7.5). Give command
¡¡¡l (see Chapter 5.2). At the first
calibration point the LED on the left flashes; adjust the humidity point
(offset) with the arrow switches to the reference value. One push of a
switch changes the output by 0.05 %RH; the change of the output
voltage or current depends on the output scaling. Press ENT switch.
The second LED from left starts flashing; press ENT again.
6.1.2
Two point calibration procedure
A two-point humidity calibration should be performed in stable conditions
using saturated salt solutions a reference.
NOTE.
If the humidity sensor has been changed, the calibration
has to be done according to the instructions in Chapter
6.1.3.
6.1.2.1
Using serial commands
Disconnect the security lock jumper!
•
Leave the calibrator and the transmitter for at least 4 hours in the
same space so that their temperatures have time to equalize. Remove
the filter cap on the transmitter.
•
Place the sensor head into the calibration hole of the LiCl bottle in the
humidity calibrator.
•
Wait for 10 minutes.
•
Give command CRH
CRH
RH : xx.x Ref1 ? yy.y
Press any key when ready...