Dynalco LST-108L Tachometer User Manual
Dynalco Measuring instruments
QUICK
GATE TIME
CALCULATION
See label on back of LST-108, LST-108L for additional information
If necessary, turn to the reverse side of the card to
calculate Signal Frequency and Gate Time.
LST-108 and LST-108L
SELF-POWERED TACHOMETER
Calibration Instructions
The LST-108 and LST-108L tachometers are normally factory-
calibrated to the customer-specified number of sensing teeth or
discontinuities, sensing speed, and desired numerical display.
}
60
Number of
Teeth
Assumes the pickup is “seeing”
the
g
ear of interest directly, not through
a step up or step down ratio
.
{
To calibrate an LST-108 or LST-108L:
1. Remove the sealing plug on the back of the housing.
2. Apply the calculated signal frequency to terminals A and B.
A Dynalco F-16 or F-15 signal generator is ideal.
3. Select the appropriate gate time range on the 4-position
switch.
See label on back of LST-108; LST-108L; or Item 3, reverse
side of card.
4. Adjust the vernier potentiometer for the desired display.
See below.
Shown with sealing plug removed
Vernier potentiometer
[clockwise to increase display reading;
counterclockwise to decrease]
4-position switch
Example:
If 3390 Hz = 1800 RPM, then gate time is 0.53 seconds.
1. Apply 3390 Hz to terminals A and B on tachometer (no polarity).
2. Turn the gate time range switch to (either) position number 2 to
select gate time range of 0.38 – 0.76 seconds.
3. Adjust the vernier potentiometer to obtain a display of 1800.
(For example: 60 /113 teeth = 0.53 sec. gate time)