Teledyne GFC-7001T - Trace CO Analyzer - Manual (Page 103)

SetupTeledyne API – Model T300/T300M CO Analyzer
Teledyne Analytical Instruments 103
5.4.4. RANGE UNITS
The GFC7001T/GFC7001TM can display concentrations in parts per million (10 6 mols
per mol, PPM) or milligrams per cubic meter (mg/m 3 , MG). Changing units affects all
of the display, COMM port and DAS values for all reporting ranges regardless of the
analyzer’s range mode. To change the concentration units:
I MPORTANT I MPACT ON R EADINGS OR D ATA
In order to avoid a reference temperature bias, the analyzer must be
recalibrated after every change in reporting units.
I MPORTANT I MPACT ON R EADINGS OR D ATA
Concentrations displayed in mg/m 3 and ug/m 3 use 0 ° C and 760 mmHg for
Standard Temperature and Pressure (STP). Consult your local regulations
for the STP used by your agency.
(Example: US EPA uses 25
o C as the reference temperature).
Once the Units of Measurement have been changed from volumetric (ppb or
ppm) to mass units (µg/m
3 or mg/m 3 ) the analyzer MUST be recalibrated, as
the “expected span values” previously in effect will no longer be valid.
Simply entering new expected span values without running the entire
calibration routine IS NOT sufficient.
This will also counteract any discrepancies between STP definitions.