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3.5.3 Trigger Level Adjust function
The TA300 also allows the user to adjust the trigger level (threshold) it uses to measure
RPM from the signal it receives from the piezoelectric pickup. This feature can be used
to compensate for excessive noise in the signal generated by vibration, electromagnetic
interference or particular characteristics of fuel pressure, injection patterns and fuel lines.
To use the Sensitivity Adjust function:
1- Turn the instrument on.
2- To perform adjustments of the trigger level while performing actual measurements,
follow the procedure as described in ‘3.4 Measurement procedures’.
3- Press and hold the
(Trigger Level Adjust) button until the minimum reading in the
display is replaced by the word ‘Threshold” followed by a set level number and then
a ‘%’ sign (see Fig. 4).
4- While holding the
(Trigger Level Adjust) button pressed, use the
(Sensitivity
Adjust increase) or
(Sensitivity Adjust decrease) buttons to adjust the % value.
Notes:
• Adjusting the trigger level of the TA300 while performing RPM measurements, provides
quick feedback on how this setting affects the response of the TA300 in any given
situation.
• The trigger level can be adjusted between 20% and 80%. The default value for the
trigger level is 50%.
• For example, if the trigger level is set to 70%, the TA300 will register an engine cycle
when the signal level from the piezoelectric pickup reaches or exceeds 70% of the
maximum signal.
• Higher trigger levels increases the noise rejection, and lower trigger level will help in
measuring RPM when dealing with inconsistent injection pulses. For most cases the
default 50% level is the optimal value.
• The values set by using the Trigger Level Adjust function are stored in internal mem-
ory, and will be retained even if the instrument is powered off, the battery is depleted
or is removed.
