Knowing the temperature to which a product has been exposed and for how long is crucial in many industries. When sterilizing surgical tools or medical devices in an autoclave or heating food prior to canning, temperature and time documentation should be maintained. Temperature monitoring assists facility managers in preventing legionella and environmental scientists in assessing the quality of rivers and streams. Temperature data recorders can be used to monitor and verify this and other comparable processes.
Temperature data logger basics
A temperature data recorder is a special sort of data logger that is created or built expressly for use with temperature probes or sensors (and in the case of a humidity and temperature logger, with humidity sensors too). A data logger is an electrical device that is capable of storing a large number of measurements. It accepts one or more sensor inputs, sampling and recording data at a specified rate, and is frequently powered by batteries. At the conclusion of the acquisition time, the logger is recovered and the data is downloaded to a PC for analysis. Certain data recorders can even wirelessly transmit measurement results to a computer or other device, obviating the need for field excursions.
Temperature data recorders are available in a wide variety of configurations and sizes.
Each temperature logger is composed of two components: a temperature sensor or sensors and a recording device that samples the sensor at predetermined intervals and stores the measurement data. This sensor can be directly linked to the recording system or placed at a distance from it.
Combining a thermistor or thermocouple with a logger in a single container results in a small, lightweight recording device. Its disadvantage is that it must be placed in the area where the temperature will be measured. Internal sensor loggers cannot be used in high-temperature circumstances because the electrical components of the device must operate within a specified operating temperature range. This does make them useful for recording transport temperatures, which may be required for shipping artwork or perishable produce such as eggs.
Using a thermocouple
Numerous temperature recorders accept direct inputs from one or more thermocouples. The OMEGA HH1384, for example, is a four-channel thermometer and data recorder that accepts thermocouples of the K, J, E, T, R, S, N, L, U, B, and C types. This enables temperature to be captured close to the thermocouple data recorder, but is ineffective when the temperature is too high or too low for the batteries or electronics. Many of these are handheld devices meant for short-term recording. Numerous general-purpose data recorders include thermocouple and thermistor inputs, allowing them to be used as thermometers.
When an external probe is used
Utilizing a temperature data logger equipped with a probe (for example, OMEGA’s OM-CP-HITEMP140-FP is a high-temperature data logger equipped with a flexible probe) eliminates the issue of taking measurements in very hot or cold situations. This enables the recorder to remain stationary while the sensor is moved. It would enable temperature logging in an oven, for example, even if the logger itself perishes.
Multiple-channel temperature recorders
General-purpose and temperature data recorders are available with up to 32 inputs (single-ended—16 differential). They are compatible with thermistors and thermocouples, as well as 2-, 3-, and 4-wire RTD temperature sensors.
Obtaining data Many data recorders equipped with sensors are designed to resemble USB drives and may be inserted into a computer’s USB port to download data. Other loggers connect through USB, but require a separate cable. Another option is to link the logger through Bluetooth® to a PC or even a mobile device. Certain data loggers can communicate with a central PC via an Ethernet network, while others communicate via wireless. Both solutions obviate the need to travel to a field data logger to retrieve the data.
Temperature measurement is critical in a variety of applications, ranging from monitoring the health of rivers and streams to ensuring sterilization procedures are performed properly. In some cases, measurements taken over an extended period of time are necessary to ascertain long-term trends. Others are curious about the highest or lowest temperature reached, as well as the duration of exposure.
Temperature and relative humidity readings
A temperature and humidity record can be quite useful for identifying inefficiencies in facility management, particularly where accurate measurement or temperature-sensitive procedures are performed. The same holds true for plant and animal propagation. Legionella protection, which can cause a potentially fatal form of pneumonia, is a critical concern for a facility manager. In applications such as these, a combination of temperature and humidity data recorders provides a time-stamped record of the observed conditions over an extended period of time.
Another instance in which a time-stamped record is beneficial is during the transfer of artworks. In this case, simply being aware that your situation is being observed may be sufficient to motivate you to exercise extra caution when logging at high temps.
While there is no precise definition of “high temperature,” a device capable of recording at temperatures more than 80°C (176°F) is often referred to as a high-temperature logger. High-temperature settings include autoclaves, pasteurization, and food and material processing. Canning food is one example. Manufacturers must demonstrate that the product has attained the minimum temperature necessary to destroy germs such as botulism in this scenario. For these situations, loggers frequently include a probe to keep the sensitive electronics cool.
Water temperature monitoring
Aquariums benefit from water temperature monitoring because it enables them to maintain a healthy habitat for their fish, many of which require a precise temperature range to survive. In a similar fashion, scientists use the temperature of rivers and streams to assess the health of those ecosystems. Both are excellent applications for a water temperature data logger, but they place distinct demands on the device.
Because the logger will be conveniently accessible within the tank, a huge memory capacity will be unnecessary, and data can be recovered by direct PC connection or Bluetooth. On the other hand, obtaining accurate data on river temperatures may require leaving the logger in place for several months. Memory capacity, battery life, and even wireless capabilities become increasingly vital in these circumstances.
Numerous goods and medications must be shipped under strictly controlled conditions to avoid degradation. By incorporating a small temperature data recorder within the things transported, a record of the conditions can be kept. This helps ensure product integrity and provides documentation in the event of a mishandling claim.
Following steps to take
With so many possibilities, it can be difficult to choose the right temperature data recorder. The most critical characteristics may be identified and the range of accessible equipment reduced only by comprehending the purpose of temperature logging. To assist with the process, OMEGA Engineering offers an online Data Logger Product Finder tool; nevertheless, if you have more questions, contact OMEGA’s technical experts for guidance on the best equipment for your unique application.