Instruction manual

Model 109SS Temperature Probe

Stainless-Steel Sheath

Diameter: 0.16 cm (0.063 in)

Length: 5.84 cm (2.3 in)

Overmolded Joint

Diameter: 1.02 cm (0.40 in)

Length: 4.24 cm (1.67 in)

Cable: Santoprene

, 0.220 in diameter

Cable/Probe Connection: ATUM

heat shrink

Macromelt

overmolded joint

Weight: 0.2 lb per 10.5 ft cable

See FIGURE 6-1, Worst-case probe and measurement errors, and FIGURE 6-2 Steinhart-Hart

linearization error. Overall probe accuracy is a combination of thermistor interchangeability,

bridge-resistor accuracy, and error of the Steinhart-Hart equation . Interchangeability is the

principle component error and is predominantly offset. Offset can be determined with a single-

point calibration. Offset can be entered in the Therm109() instruction Offset parameter. The

bridge resistor has a 0.1% tolerance with a 10 ppm temperature coefficient. At temperature

extremes, the possible error in the CR200(X) series datalogger measurement may be greater than

the error that exists in the probe.

FIGURE 6-1. Worst-case probe and measurement errors

0.1

0.2

0.3

0.4

0.5

0.6

0.7

-50 -40 -30 -20 -10 0 10 20 30 40 50 60 70

Possible Error Degrees C

Temperature Degrees C

Worst Case Errors in 109 Temperature Measurement

Thermistor

Tolerance

CR200 Bridge

Measurement

Error (0.06% of

reading + 2.4

mV)

CR200

Resolution (0.6

mV)