TC300 Heater Temperature Controller Chapter 6: Stand-Alone Operation
Page 14 CTN017856-D02
The TC300 also supports the Steinhart-Hart method to approximate the relation between temperature and
thermistor resistance when the sensor type is set to NTC2.
The Steinhart-Hart method can be described by the formula
1 π
β
οπ΄ο
π΅βln
σ°
π
σ°
ο
πΆβσ°ln
σ°
π
σ°
σ°
ο·
with T being the temperature in K (Kelvin) and A, B, and C being the Steinhart-Hart parameters. The TC300 allows
user input of the A, B, and C parameters. For thermistors that support the Steinhart-Hart method, the actual value
of A, B, and C can usually be found on their datasheets.
6.2.2. Platinum Resistance Temperature Detector (PT100 and PT1000)
The TC300 is compatible with both the 100 Ξ© (PT100) and 1000 Ξ© (PT1000) platinum resistance temperature
detector. When working with platinum sensors, set the sensor type to PT100 or PT1000 according to the actual
sensors wired to the Hirose connectors on front panel.
The TC300 measures the resistance and calculates the temperature of the PT100 and PT1000 platinum resistance
temperature detectors using the following formula:
π
οπ
ο΄
σ°
1 ο
π΄βπο
π΅βπ
οΆ
σ°
With: A = 3.9083 x 10
-3
Β°C
-1
B = -5.775 x 10
-7
Β°C
-2
T - Temperature in K (Kelvin)
R - Thermistor resistance in ο at temperature T
R
0
- 100 ο for the PT100; 1000 ο for the PT1000
The TC300 supports 2-wire and 4-wire connection for both PT100 and PT1000. When the sensor type is set to
PT100 or PT1000, select the βParameterβ option to toggle between the 2-wire and 4-wire connection setting.
As the actual resistance of platinum sensors is relatively low, we recommend using sensors that support 4-wire
connection which could alleviate the problems due to extension wire length and resistance imbalance between the
leads, providing a much more accurate measurement result.
When sensor type is set to PT100 or PT1000, the TC300 also offers the option of a user input offset to allow the
device to compensate any offset in temperature measurement.
To determine the offset value, a reference temperature measurement needs to be made with a third-party
instrument. Use the platinum sensor that is already connected to the TC300 and the reference instrument to
measure the temperature of the same item at the same spot. The PT Offset value will then be:
ππ ππππ ππ‘ ο π
ο₯οοοο₯οο‘οο
οπ
οοΌο·ο΄ο΄
With T
reference
: Temperature reading of the third-party reference instrument
T
TC300
: Temperature reading of the TC300 with platinum sensor
Figure 18 Sensor Settings for Platinum Sensors
3-wire platinum resistance temperature detectors are not compatible with the TC300.