Temperature data logger

Example of a small temperature data logger

A temperature data logger, also called temperature monitor, is a portable measurement instrument that is capable of autonomously recording temperature over a defined period of time. The digital data can be retrieved, viewed and evaluated after it has been recorded. A data logger is commonly used to monitor shipments in a cold chain and to gather temperature data from diverse field conditions.

Construction

A variety of constructions are available. Most have an internal thermistor or thermocouple or can be connected to external sources. Sampling and measurement are periodically taken and digitally stored. Some have a built in display of data or out-of-tolerance warnings. Data retrieval can be by cable, RFID, wireless systems, etc. They generally are small, battery powered, portable, and equipped with a microprocessor, internal memory for data storage, and sensors. Some data loggers interface with personal computers or smart phones for set-up, control, and analysis.

Some include other sensors such as relative humidity, wind, light, etc. Others may record input from GPS devices.

Depending on the use, governing quality management systems sometimes require calibration to national standards and compliance with formal verification and validation protocols[1]

Choices of temperature data loggers can be based on many factors, such as:

Uses

Environmental monitoring

Autonomous data loggers can be taken to diverse locations that cannot easily support fixed temperature monitoring equipment.[3] These might include: mountains, deserts, jungles, mines, ice flows, etc. Portable data loggers are also used in industry and laboratory situations where stand-alone recording is desired.

Monitor shipments

Temperature sensitive products such as foods,[4] pharmaceuticals,[5] and some chemicals are often monitored during shipment and logistics operations. Exposure to temperatures outside of an acceptable range, for a critical time period, can degrade the product or shorten shelf life. Regulations and contracts make temperature monitoring mandatory for some products.

Data loggers are often small enough to be placed inside an insulated shipping container or directly attached to a product inside a refrigerator truck or a refrigerated container. These monitor the temperature of the product being shipped. Some data loggers are placed on the outside of the package or in the truck or intermodal container to monitor the air temperature. Placement of data loggers and sensors is critical: Studies have shown that temperatures inside a truck or intermodal container are strongly affected by proximity to exterior walls and roof and to locations on the lading.[6][7]

Modern digital data loggers are very portable and record the actual times and temperatures. This information can be used to model product degradation and to pinpoint the location and cause of excessive exposure.

The measured data reveals whether the goods in transit have been subjected to potentially damaging temperature extremes or an excessive Mean kinetic temperature. Based on this data, the options may be:

Multiple replicate shipments of data loggers are also used to compare modes of shipment (routes, vendors) and to develop composite data to be used in package testing protocols.[9]

See also

References

  1. Bull, K (Winter 2008), Thermistors and Thermocouples: Matching the Tool to the Task in Thermal Validation (PDF), Journal of Validation Technology, retrieved 22 March 2012
  2. Whiteman, C. D., J. M. Hubbe, W. J. Shaw, 2000: Evaluation of an Inexpensive Temperature Datalogger for Meteorological Applications. J. Atmos. Oceanic Technol., 17, 77–81.
  3. Raab, Verana (2011), Temperature Monitoring in Meat Supply Chains 113 (10), British Food Journal, pp. 1267–1289, retrieved 22 March 2012
  4. Wessel, Rhea (July 27, 2011), DB Schenker Uses Terperature-logging Tags to Monitor Drug Shipments, RFID Journal, retrieved 22 March 2012
  5. Schafer, Howard (1978), Temperature profiles of rail transported ondnance, Naval Weapons Center, technical publication, vol 4917
  6. Goedecke, Thomas (2008), Temperature and Air Change Rates in Freight Containers During Transit (PDF), International Safe Transit Association, retrieved 29 March 2012
  7. Meyers, T (June 2007). "RFID Shelf-life Monitoring Helps Resolve Disputes". RFID Journal.
  8. Young, D (2002), ISTA Temperature Project – Data Smmary (PDF), ISTA, retrieved 22 March 2012

Books, General References

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