Sierra FLAT-TRAKTM 780S - Manual (Page 42)

Chapter 3 Operation Series 780S Instruction Manual
3-16 IM-78S-B
4. Set the multimeter to read Ohms in the 2K range. Connect the
multimeter to the terminals of J5 and J6 (temperature sensor).
Measure the resistance between J5 and J6 and record the tem-
perature sensor resistance (in Ohms) in Table 3-2.
5. Set the multimeter to read in the 200 Ohm range. Connect the mul-
timeter to terminals of J7 and J8 (velocity sensor). Measure the re-
sistance between J7 and J8 and record the velocity sensor resis-
tance (in Ohms) in Table 3-2.
6. Use the measured resistance values and the Ro and Alpha Ro
values from the Calibration Certificate to calculate the tempera-
ture for each sensor as follows:
T =
R – R
Alpha x R
T = degrees Celsius
R = measured sensor resistance
R = resistance at 0° C (from the Calibration Certificate)
Alpha = value unique to each sensor (from the Calibration Certificate)
o
o
Where
o
7. Compare the results recorded in Table 3-2. The sensors are vali-
dated if they are within 10 degrees Celsius of each other.
8. Disconnect the multimeter and replace the four-position jumper on
the sensor terminals. Make sure the jumper is securely in
place before applying power. Replace cover.
Temperature Sensor
R e s i s t a n c e
T
(from equation)
Velocity Sensor
R e s i s t a n c e
T
(from equation)
Table 3-2. Sensor Validation Results