Model 109SS Temperature Probe

The resistance of the thermistor is:

 

⎛ V

EX

⎞

R = 24,900⎜

 

−1⎟

 

 

t

⎝

V

⎠

 

The Steinhart and Hart equation is used to calculate temperature from

Resistance:

TK = A + B ln(RT )1+ C(ln(RT ))3

Where TK is the temperature in Kelvin. The Steinhart and Hart coefficients used in the Therm109 instruction are:

A= 1.129241x10-3

B= 2.341077x10-4

C= 8.775468x10-8

7.Maintenance and Calibration

The 109SS Probe requires minimal maintenance. Periodically check cabling for proper connections, signs of damage, and possible moisture intrusion. For all factory repairs and recalibrations, customers must get a returned materials authorization (RMA). Customers must also properly fill out a “Declaration of Hazardous Material and Decontamination” form, and comply with the requirements specified in it. Refer to the “Warranty and Assistance” page for more information.

8. Troubleshooting

Symptom: Temperature is NAN, -INF, -9999, -273

Verify the red wire is connected to the correct Single-Ended analog input channel as specified by the measurement instruction, the black wire is connected to the switched excitation channel as specified by the measurement instruction, and the purple wire is connected to datalogger ground.

Symptom: Incorrect Temperature

Verify the multiplier and offset parameters are correct for the desired units (Section 5). Check the cable for signs of damage and possible moisture intrusion.

NOTE For all factory repairs, customers must get an RMA. Customers must also properly fill out a “Declaration of Hazardous Material and Decontamination” form and comply with the requirements specified in it. Refer to the “Warranty and Assistance” page for more information.

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