Thermo Scientific 146i, Instruction Manual

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Thermo Fisher Scientific Model 146 i Instruction Manual 4-1
Chapter 4
Calibration
Mass Flow
Controllers
In order to calibrate the mass flow meter section of the zero or gas mass flow
controller, a NIST traceable flow meter is required. The term calibration
means determining the actual flow versus the flow setting for seven equally
spaced flows along the range of the device. The Model 146
i then corrects
the output according to an internal algorithm.
Calibration may be done with a properly calibrated flow meter. For the most
accurate calibration procedure, use a volumetric NIST traceable calibrator
with the following step-by-step calibration procedure.
1. Connect a source of clean, dry air to the inlet of the mass flow
controller.
2. Measure barometric pressure and room temperature.
3. Connect a suitable flow meter to the mass flow controller outlet.
4. Set Model 146 i to Gas Drive or Zero Air Flow Calibration as described
in the “Operation” chapter.
5. Set flow controller to 95 percent of full scale, then wait until flow meter
reading stabilizes.
6. Enter the flow meter reading using the flow input screen.
7. Repeat Steps 5 and 6 for the remaining flow settings.
If difficulty is encountered due to a flow controller malfunction, contact
Thermo
Fisher Scientific
.