Owner's manual

OM-USB-TEMP User's Guide Specifications
22
Accuracy
Thermocouple measurement accuracy
Table 4. Thermocouple accuracy specifications, including CJC measurement error
Sensor Type Maximum error Typical error Temperature range
±1.499 °C ±0.507 °C -210 to 0 °CJ
±0.643 °C ±0.312 °C 0 to 1200 °C
±1.761 °C ±0.538 °C -210 to 0 °CK
±0.691 °C ±0.345 °C 0 to 1372 °C
±2.491°C ±0.648 °C -50 to 250 °CS
±1.841 °C ±0.399 °C 250 to 1768.1 °C
±2.653 °C ±0.650 °C -50 to 250 °CR
±1.070 °C ±0.358 °C 250 to 1768.1 °C
±1.779 °C ±0.581 °C 250 to 700 °CB
±0.912 °C ±0.369 °C 700 to 1820 °C
±1.471 °C ±0.462 °C -200 to 0 °CE
±0.639 °C ±0.245 °C 0 to 1000 °C
±1.717 °C ±0.514 °C -200 to 0 °CT
±0.713 °C ±0.256 °C 0 to 600 °C
±1.969 °C ±0.502 °C -200 to 0 °CN
±0.769 °C ±0.272 °C 0 to 1300 °C
Note 4: Thermocouple measurement accuracy specifications include linearization, cold-junction
compensation and system noise. These specs are for one year, or 3000 operating hours,
whichever comes first, and for operation of the OM-USB-TEMP between 15 °C and 35 °C. For
measurements outside this range, add ±0.5 degree to the maximum error shown. There are CJC
sensors on each side of the module. The accuracy listed above assumes the screw terminals are at
the same temperature as the CJC sensor. Errors shown do not include inherent thermocouple
error. Please contact your thermocouple supplier for details on the actual thermocouple error.
Note 5: Thermocouples must be connected to the OM-USB-TEMP such that they are floating with respect
to GND (pins 9, 19, 28, 38). The OM-USB-TEMP GND pins are isolated from earth ground, so
connecting thermocouple sensors to voltages referenced to earth ground is permissible as long as
the isolation between the GND pins and earth ground is maintained.
Note 6: When thermocouples are attached to conductive surfaces, the voltage differential between
multiple thermocouples must remain within ±1.4 V. For best results we recommend the use of
insulated or ungrounded thermocouples when possible.
Semiconductor sensor measurement accuracy
Table 5. Semiconductor sensor accuracy specifications
Sensor Type Temperature Range (°C) Maximum Accuracy Error
TMP36 or equivalent -40 to 150 °C ±0.50 °C
Note 7: Error shown does not include errors of the sensor itself. These specs are for one year while
operation of the OM-USB-TEMP
unit is between 15 °C and 35 °C. Please contact your sensor
supplier for details on the actual sensor error limitations.