NOTE

While measuring zero air, a certain amount of noise or “dithering” of the concentration about the zero point will occur and is normal. This noise is typically 1-3 PPM in magnitude.

7.2.3.5. Span Calibration

The Span Calibration also allows the instrument to calibrate its internal ozone offset factor. The Span Calibration however, is done with some controlled concentration gas connected to the “Sample In” port of the M465M. It is recommended that a span gas is concentrated to around 80% of the operating range. Set the SPAN VALUE to the measured concentration of your calibration gas. This normally takes 10-15 minutes.

NOTE

A Span Calibration should only be performed with a stable source of Ozone and a reference monitor measuring the same gas supply.

If you are unsure regarding the suitability of a particular source of calibration gas, contact Customer Service at Teledyne API for assistance (see Section 12.)

See Figure 7-4shows the Span Cal menu. After the instrument has stabilized on the source of span gas, navigate to the Span Cal menu (See Figure 7-4) and Press ENT. Next enter the Span Target concentration (the actual concentration of ozone being supplied to the monitor) and press ENT. The display will next show a confirmation menu, ENT TO SPAN. Press ENT to perform the Span Calibration, or CFG to abort back to the start. If the calibration is successful, the display will return to the concentration menu and the monitor reading should change adjust to read very close to the target value. If the calibration cannot be performed, an OUT OF RANGE error will be displayed. Press ENT to confirm and the display will return to the start of the Span Cal menu.

If the OUT OF RANGE error occurs, it means the Span Cal cannot be performed because it would result in an out of range slope value for the monitor. This means that either the sensor in the monitor is malfunctioning, causing improper readings, or the actual ozone concentration being supplied to the monitor is different than the target value being entered.

P/N 06160D DCN6409 Teledyne API Model 465M O3 Monitor Instruction Manual - Page 38

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Teledyne 465M instruction manual Span Calibration