Chapter 3_____________________________________________________________________ Operation
VAISALA _____________________________________________________________________________9
Two-point calibration
The reference gases used for the two-point calibration shall represent the low
and high end of the probe's measuring range. Please, read recommendations
concerning the reference gases in
Chapter 2 Additional equipment
before
starting the operation.
Perform the two-point calibration according to the following
instructions:
1.
Connect the cable (item 2, Figure 1) to the probe to be tested.
2.
Insert the probe into the chamber (item 5, Figure 1) so that the
perforated filter cover is completely inside the chamber.
3.
Connect the PC to the calibrator with the serial cable (item 8,
Figure 1). Check the connection set-up, the serial line settings for data
transfer shall be
•
9600 baud
•
parity: 8/None
•
1 stop bits
4.
Connect the 24 VDC supply power to the connectors located on
the right-hand side of the plate (items 9 and 10, Figure 1).
5.
The following (or similar) text appears in the terminal window on
the PC screen (number of the program version can be updated):
GMT220A - Version: STD 4.08
Copyright: Vaisala Oyj, Matti Kokki, 1997-2000
>
6.
Let the calibrator settle for 10 minutes.
7.
Connect the low-end gas and adjust the flow rate of 0.6 l/min with
a screwdriver (item 4, Figure 1). Flush the chamber with the gas for 5
minutes.
8.
Give the password by typing
PASSWORD 5120<
CR
>
