Restek 22839, Инструкция по эксплуатации, Страница: 7 / 24

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10.0 Technology
The Leak Detector measurement is based on thermal conductivity comparisons between the probe air and a reference air. The device
employs a dual thermistor technology which measures the ratio of [probe]:[reference] heat exchange values and displays the results on
an LED scale (Figure 4). Under ideal operating conditions, a ratio of 1:1 indicates identical air samples for both [probe] and [reference],
and therefore no leak is present.
Because of slight differences in air temperature and/or humidity between the reference inlet (Figure 1) and the probe tip, a small
response indicated by a single red or yellow LED light is generally insufficient to positively identify a gas leak. Small to moderate leaks
are reliably indicated with 4 red LED lights, larger leaks are indicated with all red LED lights or yellow LED lights lit and the continu-
ous alarm is audible.
LEFT: Dual analysis is achieved with heater
elements positioned in separate flow chambers.
RIGHT: Probe and reference air streams are
simultaneously monitored for thermal
conductivity. Differences in air composition
are indicated by differences in the heater
element currents.
Figure 4
Schematic layout of the Leak Detector technology.
www.restek.com
- 7 -
10.0 Technology
The Leak Detector measurement is based on thermal conductivity comparisons between the probe air and a reference air. The device
employs a dual thermistor technology which measures the ratio of [probe]:[reference] heat exchange values and displays the results on
an LED scale (Figure 4). Under ideal operating conditions, a ratio of 1:1 indicates identical air samples for both [probe] and [reference],
and therefore no leak is present.
Because of slight differences in air temperature and/or humidity between the reference inlet (Figure 1) and the probe tip, a small
response indicated by a single red or yellow LED light is generally insufficient to positively identify a gas leak. Small to moderate leaks
are reliably indicated with 4 red LED lights, larger leaks are indicated with all red LED lights or yellow LED lights lit and the continu-
ous alarm is audible.
LEFT: Dual analysis is achieved with heater
elements positioned in separate flow chambers.
RIGHT: Probe and reference air streams are
simultaneously monitored for thermal
conductivity. Differences in air composition
are indicated by differences in the heater
element currents.
Figure 4 Schematic layout of the Leak Detector technology.