Testing a 110S temperature probe

Tools Required:

• 9V battery
• Digital voltmeter (DVM)
• Reference Temperature Probe (Thermometer)

Instructions:

The 110S will run on an excitation voltage from 4 to 25 V DC and will draw no more than 300uA.

Current Check:

Connect a 9V battery in series with a current meter to power the 110S black (-) and red (+) leads. If the current is higher than 300uA, something is wrong and the sensor should be replaced.

Signal Output Check:

• Power the probe with the 9 V battery connected to the 110S black (-) and red (+) leads.
• Read the output voltage between the black (-) and signal (clear) leads.
• Convert that voltage into a temperature (using the formulas below) and compare against a reference thermometer.
  Degrees F = (Vout x 100) - 123.5
  Degrees C = (Vout x 55.55) - 86.38

If the 110S is within 2 degrees of the reference it is good. Sometimes the perceived problem is confusion regarding the conversion from volts to degrees.

Example Degrees F:

An output reading of 2.140 Volts is taken across the black and clear leads.
Degrees F = (2.140 x 100) -123.5
Degrees F = 90.5

Example Degrees C:

An output reading of 2.140 Volts is taken across the black and clear leads.
Degrees C = (2.140 x 55.55) -86.38
Degrees C = 32.5