Ametek Land LMG MkII, User Manual

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4 - 3 User Guide
LMG MkII Signal Processor
4.3 Peak Picker
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. a steel slab on a
rolling mill where parts of the surface are covered with scale. The ‘clean’
area will be at the higher (i.e. true) temperature. The Peak Picker used in
Landmark Graphic 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 ‘Sample’ mode the peak picker samples for a pre-
defined period, then outputs this value.
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. 2-5 and Fig. 2-6.
For typical Peak Picker and Peak Sampler responses, see Fig. 4-3 and
Fig. 4-4 respectively.