Ametek Land Landmark Graphic AE, Руководство пользователя

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Page 46
Signal Processor User Guide
LMG AE
4 Time Function Processing
4.1 Peak Picker (not available on AET/AQT channels)
The Peak Picker function can be used to monitor the highest temperature
measured by the thermometer. This feature is useful especially for moving
targets and/or where the target is obscured partially e.g. by patches of
oxidation an an otherwise un-oxidised surface. The ‘clean’ area will be at the
higher (i.e. true) temperature. The Peak Picker used in Landmark Graphic AE
processors has the following features.
Threshold level Temperature above which the Peak Picker is active, used in
conjunction with the ON and OFF delay.
ON delay Time period between the temperature rising above the
threshold level and the Peak Picker function switching on.
OFF delay Time period between the temperature falling below the
threshold level and the Peak Picker function switching off.
In ‘Hold’ mode, at the end of the ‘OFF’ delay, the temperature
output value is held constant until the temperature input next
rises above the threshold level.
In ‘Reset’ mode, at the end of the ‘OFF’ delay, the temperature
output signal falls to ‘under-range’ until the temperature input
next rises above the threshold level.
In ‘Peak Sample’ mode, the temperature is sampled in
predefined intervals and outputs the peak value of the most
recent interval.
Decay rate A user-adjustable value at which the stored temperature
output signal decays.
The Peak Picker function can be reset via the CMD (Command) input. The
CMD input connections and operation is shown in Fig. 7 and Fig. 8.
For typical Peak Picker responses, see Fig. 32.
Peak Sample This function allows the unit to peak pick for a user-defined
period before the output/display are updated. (Interval 10 to
250 seconds in 1second steps).
For typical Peak Sample responses, see Fig. 33.