Practical Application; The Unit "Ppm; Detecting A Leak (Schematic Diagram) - Herth+Buss SelectH2 mini Bedienungsanleitung

Operating Instruction

9. Practical application

9.1 The unit "ppm"

The high sensitivity of the SelectH
gas detector makes it possible to detect
traces of gases in the ppm range. 1 ppm is
the quantity of 1 cm
for example. The SelectH
measures up to 999 ppm in this dimension.
In the transition to 1,000 ppm, the display
switches to the vol % range and changes to
0.1 vol % (see the comparison values in the
following table).
1 ppm = 1 part per million
100 % = 1,000,000 ppm
10 % = 100,000 ppm
1 % = 10,000 ppm
0.1% = 1,000 ppm
0.01 % = 100ppm
0.001 % = 10 ppm
0.0001 % = 1 ppm

9.2 Detecting a leak (schematic diagram)

The escaping quantity of gas determines the
spread width. However, as the spread range is
unknown, every connection in the accessible
parts of the pipe must be examined carefully
if a gas odour is reported. If the sensor head
of the device is held in the "gas cloud" , the
gas present is sucked in, detected by the
gas-sensitive semiconductor, and indicated
on the display. Depending on the strength of
the gas concentration, the gas concentration
display will take around 2 – 3 seconds.
When testing, this means that briefly coming
close to the joint or screw connection is not
enough to detect small gas leaks.
31
mini
2
of gas in 1 m of air,
3 3
mini gas detector
2
95980019
Gas
EN