M4557 - Model 9210 Nitriding Controller
SSi Manual SERIES 9210-M4557-Nitriding Page 58 of 58
4.1 General Frequency
The Nitriding Sample Cell based analyzer is an extremely stable instrument and requires only very
occasional calibration. The exact calibration period depends on the type of sample and environment the
instrument is placed in. We recommend that any quality assurance procedures written for the instrument
are written to allow verification as opposed to calibration. Verification involves checking that the instrument
provides the correct analysis of a standard gas within the limits of the instrument and only calibrating when
a result outside of limits is produced. The frequency of the verification would need to be in line with the
quality regime being operated by the user.
4.2 Calibration method
NOTE: Calibration requires a computer (laptop) with an available serial port and HyperTerminal software.
Introduce the calibration gas in the same way as the normal sample.
The sample cell should be isolated from the process gas and the calibration
gas introduced into the Sensor at the correct flow rate. Note that pressure regulators and gauges that may
be in the calibration gas lines all have a certain amount of dead space within them and so may require
purging for several minutes before the delivered gas matches that of the cylinder contents. Only when the
reading is steady has the dead space been purged.
The recommended order of calibration is:
逸
Zero=xxx.xx<CR><LF>.command where xxx.xx = 0 (See appendix 1)
The Zero point will use 100% Nitrogen
逸
Span=xxx.xx<CR><LF>. command where xxx.xx = 100 (See appendix 1) The Span point will use
100% Hydrogen