MIXCHEK
Operation
Teledyne
Analytical
Instruments
25
Operation
3.1 Operation/Start-up
Using the
MIXCHEK
analyzer basically involves three steps:
•
Powering up the instrument
•
Set the O2 Span
•
Attach a sample gas
3.1.1 Powering Up
Turn the instrument on using the power switch and allow it to
operate for 30 seconds. If your instrument has an oxygen sensor
installed, it should indicate an oxygen reading of 17% to 25% oxygen
when exposed to flowing air. If the reading is not within this range,
verify that the oxygen sensor is installed and that it is exposed to air.
3.1.2 Setting the O2 Span
The
MIXCHEK
is shipped calibrated from the factory. The
helium section will rarely require any further calibration. If the helium
sensor is replaced, then calibration of the helium sensor is required.
Refer to Section 2.7 for calibrating the helium sensor.
The oxygen section, however, must be calibrated before use. It
should be calibrated each day prior to use. To calibrate the unit, turn the
instrument on and let it operate for 30 seconds. Make sure that the
analyzer is exposed to flowing air, and then adjust the O2 SPAN control
until the oxygen display indicates 20.9% oxygen. See also Section A.3
in the Appendix. The analyzer is now ready for service.
3.1.3 Attaching the Sample Gas
See Figure 3-1. On the portable unit, attach the sample tube to the
gas source and adjust the flow rate to 0.2—2.0 SLPM. For the wall
mount unit, attach the sample gas to the sample in port and adjust the
flow to 0.2—2.0 SLPM. The actual sample flow rate is not critical, but it
is important that the flow rate does not exceed 2.0 SLPM. The