109SS-L Stainless-Steel Temperature Probe for Harsh Environments
Rugged, Accurate, Versatile
Can be used in a variety of applications
weather applications water applications energy applications gas flux & turbulence applications infrastructure applications soil applications


The 109SS is a rugged, accurate probe that measures soil or water temperature from -40° to +70°C. The 109SS consists of a thermistor encased in a sheath made from grade 316L stainless steel. The rugged stainless-steel sheath protects the thermistor, allowing you to bury or submerge the 109SS in harsh, corrosive environments. This probe also has a fast time response, and it can be easily interfaced with our dataloggers.

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Benefits and Features

  • Designed for harsh, corrosive environments
  • Fast response time
  • Wide temperature measurement range
  • Easy to install or remove
  • Compatible with the CWS900-series interfaces, allowing it to be used in a wireless sensor network
  • Compatible with most of our current and retired dataloggers

The "-L" on a product model indicates that the cable length is specified at the time of order.


Detailed Description

The 109SS's thermistor can survive temperatures up to 100°C, but the overmolded joint and cable should not be exposed to temperatures hotter than +70°C.


Sensor Description Micro-BetaCHIP Probe 10K3MCD1, 0.5 mm (0.018 in.) diameter, 10 kohm at 25°C
Temperature Measurement Range -40° to +70°C
Thermistor Temperature Survival Range -50° to +100°C
Overmolded Joint and Cable Temperature Survival Range -50° to +70°C
Maximum Submergence 45.7 m (150 ft) or 434 kPa (63 psi)
Interchangeability Error
  • ±0.6°C tolerance (-40°C)
  • ±0.38°C tolerance (0°C)
  • ±0.1°C tolerance (25°C)
  • ±0.3°C tolerance (50°C)
  • ±0.4°C tolerance (70°C)
Steinhart-Hart Linearization Error ≤ 0.02°C (-40° to +70°C)
Time Constant in Air
  • 31 s (still air)
  • 7.5 s (air @ 3 m/s)
  • 0.5 s (antifreeze/water rolling)
Cable Description 0.56 cm (0.22 in.) diameter with Santoprene jacket
Cable/Probe Connection “ATUM” heat shrink, “Macromelt” overmolded joint
Stainless-Steel Sheath Diameter 0.16 cm (0.063 in.)
Stainless-Steel Sheath Length 5.84 cm (2.3 in.)
Overmolded Joint Diameter 1.02 cm (0.40 in.)
Overmolded Joint Length 4.24 cm (1.67 in.)
Weight 0.1 kg with 3.2 m cable (0.2 lb with 10.5 ft cable)


Datalogger Considerations


The instruction set for our CR200(X)-series, CR800-series, CR1000, and CR3000 dataloggers contains the Therm109 instruction for measuring the 109SS probe. Programming is more complicated for other dataloggers because they must use generic measurement instructions.

Compatible Contemporary Dataloggers

CR200(X) Series CR800/CR850 CR1000 CR3000 CR6 CR9000X

Compatible Retired Dataloggers

CR500 CR510 CR10 CR10X 21X CR23X CR9000 CR5000 CR7X

Installation Considerations

Soil Temperature

The 109SS is suitable for shallow burial only. Placement of the sensor’s cable inside a rugged conduit may be advisable for long cable runs—especially in locations subject to digging, mowing, traffic, use of power tools, or lightning strikes.

Water Temperature

The sensor can be submerged to 46 m (150 ft) or 63 psi. Please note that the 109SS is not weighted. Therefore, the installer should either add a weighting system or secure the sensor to a fixed, submerged object, such as a piling.

Frequently Asked Questions

Number of FAQs related to 109SS-L: 4

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  1. Not every sensor has different cable termination options. The options available for a particular sensor can be checked by looking in two places in the Ordering information area of the sensor product page:

    • Model number
    • Cable Termination Options list

    If a sensor is offered in an –ET, –ETM, –LC, –LQ, or –QD version, that option’s availability is reflected in the sensor model number. For example, the 034B is offered as the 034B-ET, 034B-ETM, 034B-LC, 034B-LQ, and 034B-QD.

    All of the other cable termination options, if available, are listed on the Ordering information area of the sensor product page under “Cable Termination Options.” For example, the 034B-L Wind Set is offered with the –CWS, –PT, and –PW options, as shown in the Ordering information area of the 034B-L product page.

    Note: As newer products are added to our inventory, typically, we will list multiple cable termination options under a single sensor model rather than creating multiple model numbers. For example, the HC2S3-L has a –C cable termination option for connecting it to a CS110 instead of offering an HC2S3-LC model. 

  2. Most Campbell Scientific sensors are available as an –L, which indicates a user-specified cable length. If a sensor is listed as an –LX model (where “X” is some other character), that sensor’s cable has a user-specified length, but it terminates with a specific connector for a unique system:

    • An –LC model has a user-specified cable length for connection to an ET107, CS110, or retired Metdata1.
    • An –LQ model has a user-specified cable length for connection to a RAWS-P weather station.

    If a sensor does not have an –L or other –LX designation after the main model number, the sensor has a set cable length. The cable length is listed at the end of the Description field in the product’s Ordering information. For example, the 034B-ET model has a description of “Met One Wind Set for ET Station, 67 inch Cable.” Products with a set cable length terminate, as a default, with pigtails.

    If a cable terminates with a special connector for a unique system, the end of the model number designates which system. For example, the 034B-ET model designates the sensor as a 034B for an ET107 system.

    • –ET models terminate with the connector for an ET107 weather station.
    • –ETM models terminate with the connector for an ET107 weather station, but they also include a special system mounting, which is often convenient when purchasing a replacement part.
    • –QD models terminate with the connector for a RAWS-F Quick Deployment Station.
    • –PW models terminate with the connector for a PWENC or pre-wired system.
  3. Many Campbell Scientific sensors are available with different cable termination options. These options include the following:

    • The –PT (–PT w/Tinned Wires) option is the default option and does not display on the product line as the other options do. The cable terminates in pigtails that connect directly to a datalogger.
    • In the –C (–C w/ET/CS110 Connector) option, the cable terminates in a connector that attaches to a CS110 Electric Field Meter or an ET-series weather station.
    • In the –CWS (–CWS w/CWS900 Connector) option, the cable terminates in a connector that attaches to a CWS900-series interface. Connection to a CWS900-series interface allows the sensor to be used in a wireless sensor network.
    • In the –PW (–PW w/Pre-Wire Connector) option, the cable terminates in a connector that attaches to a prewired enclosure.
    • In the –RQ (–RQ w/RAWS Connector) option, the cable terminates in a connector that attaches to a RAWS-P Permanent Remote Automated Weather Station.

    Note: The availability of cable termination options varies by sensor. For example, sensors may have none, two, or several options to choose from. If a desired option is not listed for a specific sensor, contact Campbell Scientific for assistance.

  4. To incorporate a sensor that is compatible with wireless sensor interfaces into a wireless network, a CWS900-series wireless sensor interface is needed, as well as an A205 CWS-to-PC interface to configure it. 

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