sensor fault，need to change sensor

The analog output module is damaged, it is advice to repair to manufacturer

Possible sensor drift, resulting in numerical values, is proposed to calibrate the zero point

With Magnetic pen  long press "FUNC"  for about 5 seconds, Press button ▲ (plus 1), ▼ (minus 1) and◀(left)" regulation to display "1111", press "FUNC" 2 times, enter "ZERO" zero adjustment menu, press the “◀” into numerical display "L" at the beginning the "XX" is not zero, "Press ▼ (minus 1), which shows the number reduced to 0 so far.

With Magnetic pen  long press "FUNC" button for about 5 seconds, Press ▲ (plus 1),▼ (minus 1) and ◀(left)" regulation to display "1111", press "FUNC" 1 times, enter "SPAN" zero adjustment menu, press “◀” into "H" at the beginning "XX" the existing gas concentration, Pressing ▼ (minus 1), which shows the number reduced to 0 so far.

With Magnetic pen long press "FUNC" button for about 5 seconds, Pressing ▲(plus 1) ,▼ (minus 1) and◀ (left)" regulation to display "1111", press "FUNC" 5 times, into "20-04" the current adjustment menu, press ▲ (plus 1 ),and ▼minus 1 in order to regulate the current between the “I+”and “GND”is 4mA, at the same time zero calibration of controller;Pressing ◀ (left), pressing  ▲ (plus 1), ▼ (minus 1)" regulation of current between the “I+”and “GND”is 20mA. At the same time, the range of the controller calibration (calibration to full range).

Sensor sensitivity decreased, suggested replacement.