The 105E consists of a 24-gage, shielded, type E thermocouple wire that typically is used to measure soil temperature. Because the thermocouple junction is electrically isolated from the media being measured, you can avoid measurement errors caused by differences in ground potential.
Read MoreType E thermocouples are comprised of a chromel wire and a constantan wire joined at a measurement junction. A voltage potential is generated when the measurement end of the thermocouple is at a different temperature than the reference end of the thermocouple. The magnitude of the voltage potential is related to the temperature difference. Therefore, temperature can be determined by measuring the differences in potential created at the junction of the two wires.
A reference temperature measurement (typically measured at the datalogger wiring panel) is required. Options for measuring the reference temperature include:
Type | Chromel-Constantan |
Typical Output | 60 μV/°C |
Accuracy | Refer to the Thermocouple Measurement section in the data logger manual. |
Operating Temperature Range | -55° to +125°C (of TPE outer jacket) |
Probe Diameter | 0.8 cm (0.3 in.) |
Plug Dimensions | 1.8 x 3.3 x 1.0 cm (0.7 x 1.3 x 0.4 in.) |
Weight | 90 g (0.2 lb) with 3.05-m (10-ft) cable |
Please note: The following shows notable compatibility information. It is not a comprehensive list of all compatible products.
Product | Compatible | Note |
---|---|---|
CR1000 (retired) | ||
CR1000X | To obtain the highest accuracy, a high-accuracy junction measurement is required, such as that obtained using a 109 Temperature Probe or a Granite™ Temp 120. | |
CR300 | ||
CR3000 (retired) | ||
CR310 | ||
CR350 | ||
CR6 | To obtain the highest accuracy, a high-accuracy junction measurement is required, such as that obtained using a 109 Temperature Probe or a GRANITE™ TEMP 120. | |
CR6 | ||
CR800 (retired) | ||
CR850 (retired) |
The 105E is typically buried in the soil or other media. At the desired depth, the sensor should be placed horizontally to avoid thermal conduction between the surface and measurement junction. Placement of the sensor cable inside a rugged conduit may be advisable for long cable runs in locations subject to digging/mowing or lightning strikes.
If large numbers of 105Es need to be measured, the AM25T Thermocouple Multiplexer is recommended.
The 105E is measured by the TCDiff instruction in CRBasic and by Instruction 14 (Differential Thermocouple) in Edlog. One differential channel per probe is required; a thermocouple reference junction at the data logger is also required. The CR200(X)-series, CR500, and CR510 dataloggers do not have thermocouple measurement instructions and are therefore not compatible with the 105E.
Number of FAQs related to 105E-L: 5
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The 105E-L is only as portable as the data acquisition system. Typical data acquisition systems are either permanent or semi-permanent; therefore, the 105E-L is intended for in-situ, long-term measurements.
The correct Short Cut entry for the 105E-L is 105E (chromel-constantan) Thermocouple. This selection provides sensor-specific information, such as the color-coded wiring diagram and program annotation. However, the Type E (chromel-constantan) Thermocouple entry will produce the same measurement instruction.
Yes. A reference temperature is required for the 105E-L thermocouple measurement. The datalogger wiring panel temperature is an appropriate reference temperature when the 105E-L is wired directly to the datalogger. Additional considerations are necessary if the 105E-L is being measured on a multiplexer. For more information, refer to the “Thermocouple Measurement” section in the AM16/32B Relay Multiplexer Instruction Manual.
The TPE outer jacket on the 105E-L has an operating temperature range of -55°C to +125°C.
There are many sources for Type E thermocouple reference tables available online. One example is provided by OMEGA in the "Revised Thermocouple Reference Tables."