Crowcon Tetra MO7237, Руководство пользователя, Страница: 25 / 36

VII. Maintenance and Calibration
Tetra is designed to operate almost maintenance free under most conditions.
However, some small items of routine maintenance are recommended.
General
To keep the display panel and operator button free from dirt build up, regularly
wipe over your Tetra unit with a damp cloth.
Filter
Inspect the front filter at regular intervals for dirt or damage. Replace with a
new filter/front grille if necessary, part number CO1852.
Zero and calibration
Tetra is supplied with an auto zero function on start-up. This function can
be configured to operate automatically, on user confirmation (see quick start
guide), or can be disabled. This configuration can be set with the Crowcon
Portables PC software, see section VIII. Tetra also has a zero function in the
menu. See section II.4.
Crowcon recommends, as a minimum, a monthly gas test to confirm sensor
operation. A test gas of known composition, needs to be applied, to verify sen-
sor response and alarm function.
Instrument calibration of all sensors should be performed at 6 month regular
intervals.
Calibration method
Tetra calibration can either be performed using the Portables PC software or
by use of the Gas Test Accessory Kit. Using the Portables PC software allows
calibration using either single gas mixtures, and calibrating each sensor in turn,
or using a multigas mixture for simultaneous calibration. The Gas Test Accessory
Kit allows calibration on a quad gas mixture for the standard 4 gas combina-
tions of flammable, oxygen, carbon monoxide and hydrogen sulphide.
Calibration and Gas Testing require the use of the correct type of flow plate as
follows:
Non pumped units - use either the standard flow plate or the clip on
calibration flow plate C011005
Pumped units with software version 1V07 or lower. The pump is
Tetra Maintenance and Calibration