Thermo Electron 48C, Instruction Manual

Page: 105 / 204

Chapter 4 Calibration
4-3
Pressure Regulator for CO Standard Cylinder
The regulator used must have a nonreactive diaphragm and internal parts, as well as a
suitable delivery pressure.
Mixing Chamber
A chamber constructed of glass, Teflon, or other nonreactive material, and designed to
provide thorough mixing of CO and diluent air for the dilution method is required.
Output Manifold
The output manifold should be constructed of glass, Teflon, or other nonreactive material,
and should be of sufficient diameter to ensure an insignificant pressure drop at the
analyzer connection. The system must have a vent designed to ensure atmospheric
pressure at the manifold and to prevent ambient air from entering the manifold.
PRE-CALIBRATION
Prior to calibration, be sure the Model 48C is operating properly. The Model 48C's
internal diagnostics makes this a quick and simple process. Turn on the instrument and
allow it to stabilize for one hour. Perform the service checks of Chapter 5 “Preventive
Maintenance.” Select the operating range and the averaging time of the Model 48C.
CALIBRATION
Connect Instrument
Connect the Model 48C to be calibrated, and the calibration equipment as shown in
Figure 4-1. If an optional sample line filter is used, the calibration must be performed
through this filter. Ensure that the flow rate into the output manifold is greater than the
total flow required by the analyzer and any other flow demand connected to the manifold.