Teledyne T201 manual Zeroing the Analyzer, Step No Action Comment

Calibration Procedure Teledyne API Model T201 NH3 Analyzer Operator Manual

2.1ZEROING THE ANALYZER

The analyzer can be zeroed by either applying zero air straight to the sample port or through the optional Zero/Span valves, if installed. It is important to remember that if the analyzer was previously sampling ammonia gas, prior to conducting a Zero calibration, it will take some period of time before the zero baseline is reached. The process of zeroing the analyzer consists of delivering dry zero air to the analyzer. The operator then manually zeros the TNx and NOx channels individually through the user interface. The following Tables outline the steps necessary to zero the analyzer.

Table 2-1. Zero Calibration Procedure – Zero Gas through the SAMPLE Port

Important: Each channel (TNx and NOx) must be zeroed individually

Step No.	Action	Comment
1.	Press CAL	The T201 enters the calibrate mode from sample
		mode. Confirm zero gas is flowing past the sample
		port.
2.	Channel Selection	Press TNX or NOx then Press ENTR.
3.	Range Selection	Press LOW or HIGH range then Press ENTR.
		Always calibrate the LOW range, section 3.0 below.
4.	NH3 STB Reading	Wait for the displayed stability reading to fall below
		1.0 PPB. The lower the stability reading the better the
		zero value.
5.	Press ZERO	If you change your mind after pressing ZERO, you
		can still press EXIT without zeroing the instrument.
		You don’t have to enter concentration values. The
		analyzer knows to apply 0 PPB.
6.	Press ENTR	Pressing ENTR actually adjusts the Offset value for
		the selected channel.
7.	Press EXIT	The T201 returns to sampling mode.
8.	Check	All displayed concentrations should read zero. The
	Concentrations	offset values should be close to zero (-20 to 150 mv)
	/Offsets

16 07271B DCN6646