n. Hold calibration check switch (10) in CHECK position. Observe the reading on the digital display (2)
and observe that this number is the same (within 2 + ppm) as the number recorded on the label (6)
affixed to the interior of the control module.
This number, the calibration check number, is used as the standard reference until
the OCA is recalibrated or serviced and a new calibration check number is
established. Although the ppm value of the effluent may vary during normal
number is equal to the difference between the digital reading obtained when the
Calibration Check Switch is in the CHECK position and effluent ppm digital read
o. Release the Calibration Check Switch (10) and observe that the Digital Display (2) still reads zero
p. Close and secure side panel cover (4) of control module (3) with two machine screws (5).