A sample of gas is drawn into the sample chamber using the hand pump. Any combustibles
land on the surface of the hot wire and burn increasing the temperature of the wire
thereby increasing the resistance. This causes an imbalance in the wheatstone bridge
arrangement indicated on the display. This display is scaled in percent lower explosive
limit and is calibrated for hydrocarbons. Note that the unit will operate against
any combustible gas although the readout would be erroneous.
calibration gas is used to check the accuracy of the meter. In addition the unit
must be landed on a regular basis for formal calibration.
The scale used in the explosimeter is marked in terms of lower explosive or flammable limit and as a percentage of the lower limit (LEL). The scale may also be marked in parts per million (p.p.m).
0 comments:
Post a Comment