ACOEM Met One Instruments GAS-1060, User Manual

Page: 96 / 164

Serinus 60 User Manual 3.0
Page 96
recommends the use of a dilution calibrator and a certified cylinder of NO
2
at an appropriate
concentration (typically a cylinder of 40 to 100 ppm, balance in Nitrogen).
Equipment Required

Gas Dilution Calibrator (such as a Serinus Cal 1000).

A NO
2
gas cylinder reference standard

Zero Air Generator
Procedure
1. Connect your calibration system to the Calibration Port of the instrument (Ecotech recommends
the Serinus Cal 1000, refer to Figure 43).
2. Generate and record the displayed span concentrations for (at least) five stepped points (of
known concentrations) evenly spaced across the instruments measurement range (see the
example below).
3. Then using a program such as MS Excel, create an X Y scatter plot of expected concentration
versus the recorded instrument response and use linear regression to calculate the line of best fit
and the correlation factor (R
2
) – refer to the users local applicable standards.
Example for an instrument measurement range of 500 ppb:
a. For the 1st concentration, set the gas dilution calibrator to supply 400 ppb NO
2
gas to the
instrument.
b. Allow the instrument to sample the calibration gas until a prolonged stable response is
achieved (the amount of time this takes is impacted by the calibration setup). Record the
instrument response.
c. Repeat the above steps using concentrations of 300ppb , 200ppb , 100ppb and a Zero point.
d. Graph the results and use linear regression to determine a pass or fail as per your applicable
local standards.
𝑦 = 𝑚𝑥 + 𝑐
Note: To highlight hysteresis errors, it is advisable to run the multipoint check in both descending
and ascending order - refer to applicable local standards.