What Are Data Loggers Used For?

A data logger is a compact, self-contained electronic unit that measures and records a stream of data. Modern data loggers are highly configurable, in terms of the types of data they can record, how they transmit data, and how they can be integrated into large, complex, and dynamic networks.

Often, they’re used to monitor environmental conditions, like temperature, humidity, and pressure. Data loggers are also used in industrial manufacturing to characterize and control process units, for example measuring tank level, pH, power draw, or other important parameters. Modern electrical control systems, such as those used for automation in cars and airplanes, can have embedded data loggers that record operational conditions.

Data loggers are increasingly being used for more advanced applications. For example, large networks of data loggers can be integrated with AI-based analysis tools to plan logistics for complex supply chains. 

Pharmaceuticals

Data loggers play an important role in several areas related to pharmaceuticals. Let’s start with R&D and manufacturing. Here, data loggers are used to monitor operating conditions within individual process units, like reactors, ovens, and packaging machines. This monitoring data is used to painstakingly develop and characterize the manufacturing process during R&D. When pharmaceuticals are approved for sale, the same monitoring data is continuously collected during large-scale manufacturing to ensure that each step in the process is running in control.
The procedure of mapping the manufacturing process, then controlling each step using in-process monitoring is known as process validation. This approach is used in other industries, particularly those where the quality of each unit coming off of the manufacturing line cannot be directly tested. Instead, product quality is ensured by consistently monitoring and controlling the manufacturing process. Since validation is critical for human safety, this is an area that is regulated and enforced by the FDA.
After pharmaceutical products leave the factory, data loggers are used for monitoring conditions during transportation and storage, to make sure that conditions are appropriate for the product and its packaging.
Vaccines are an important example, since they must be held within specified temperature windows to maintain effectiveness. Vaccines are distributed via temperature controlled supply chains known as cold chains, with end-to-end temperature monitoring and control. The CDC, WHO, and the VFC (Vaccines for Children) program also provide recommendations for the use of data loggers in locations where vaccines are stored and administered. Given the intense focus on vaccine deployment currently, the most common answer for “What are data loggers used for?” includes safeguarding the supply of temperature-sensitive vaccines.
Food and Beverage
Similar to pharmaceuticals, data loggers are used to monitor the temperature and humidity in areas where perishable foods are made, handled, and stored. Monitoring in this area was standardized by the implementation of the Food Safety Modernization Act (FSMA) in 2011. The FSMA incorporates practices known as Hazard Analysis and Critical Control Points (HACCP), a central principle of which is monitoring and control of the entire process of food production, transportation, and storage to minimize risk to the consumer.
This system-wide approach to food safety requires the widespread use of automated monitoring, specifically in environments where perishable foods are made and stored. Data loggers are ideally suited for this, and can be designed and implemented to ensure regulatory compliance.
A challenging aspect for transporting food is the wide diversity of temperature requirements for different types of foods that are shipped to the same location. While single-temperature shipping containers are the most common type, multi-temperature shipping containers, which require monitoring of each temperature zone, are becoming more prevalent.
Diverse humidity requirements also present a challenge for monitoring and control systems. For example, a relative humidity of 85-95% is used to maintain freshness for many types of produce, while dry goods require humidity of <15%. Some types of food packaging are also sensitive to humidity.
Automotive
Data loggers are seeing increasing use in the automotive industry. One example is the monitoring of emission levels from diesel trucks, which has been an area of focus for regulators. For large diesel trucks, the EPA currently requires the use of onboard control systems to monitor the health of devices that reduce the amount of particulates and NOx released into the environment, among others. In the future, this may expand to direct monitoring of greenhouse gas emissions.
During engine and vehicle testing, data loggers are used to monitor operating conditions including temperature, RPM, and fuel consumption, in order to precisely measure and control test conditions. Data loggers are also used to monitor fleet vehicles on the road, for example recording speed, throttle and brake settings, and GPS location.
Any car sold in the US after 1996 has an OBD-II system (the industry standard for on-board diagnostics) that measures operating conditions and records errors. Data loggers can be connected to an OBD-II port to collect this data, which can be useful for troubleshooting, tuning, and monitoring for insurance purposes.
Modern cars with onboard data logging and internet access (telemetry) provide a new and potentially interesting data stream. These cars can be configured to upload information on driving habits and vehicle performance to a central location, where it can be combined into a large data set that represents the entire population of vehicles. Analyzing this data can provide new insights that are useful for future car designs, writing new regulations, and planning charging networks for electric vehicles.
Aerospace
In the manufacturing of aerospace equipment, the AS9100 quality standard requires monitoring of manufacturing environments, similar to pharmaceuticals. This includes monitoring the temperature and humidity of assembly areas, which can be important for fabrication of composites and other advanced materials. The standard also requires monitoring utilities, like the flowrates and pressures of process fluids. Data loggers have the ability to automate these tasks, making them more efficient and reliable.
Data loggers are also used to measure and record a variety of operating and environmental conditions while aerospace equipment is in the field, either during development and testing, or in routine operation. Ambient conditions like air temperature, humidity, and pressure are collected to characterize the environment, while specialized loggers measure internal parameters like operating temperatures, acceleration, shock and vibration, mechanical loads, and others.
An important aspect of data loggers used for aerospace is their resistance to damage by vibration and extreme temperatures.
Agricultural Technology
There are a number of areas in agriculture and horticulture where the information provided by data loggers is useful for improving productivity and reducing cost. One is the monitoring of weather and soil conditions to make informed decisions about planting, pesticide application, and irrigation. Weather stations equipped with remote data loggers can provide valuable information about the microclimate of specific areas. Monitoring the concentrations of specific elements in soil can be used to target specific fertilizer applications.
For livestock, data loggers can be used to automate spot checks of temperature and humidity, ensuring the comfort and health of animals either in indoor and outdoor environments, in incubators, or in transport vehicles. Data loggers are also used to monitor animal feed storage to avoid spoilage.
Handling and transport of agricultural products intended for human consumption like fresh fruits and vegetables are covered by ‘Good Agricultural Practice’ (GAP) programs that are harmonized with the FSMA regulations we talked about earlier. These programs include voluntary inspections that allow agricultural suppliers to demonstrate adherence to safety practices, including monitoring to ensure safe storage of perishable foods.
Water Treatment
Whether to treat municipal drinking water supplies, or process industrial wastewater effluents before discharge, water treatment processes are important for the safety and health of people and the environment. Water treatment is a good example of an industrial process that benefits from the automation and reliability provided by data loggers.
In water treatment plants, data loggers are commonly used to measure water temperature, tank levels, pressure, and pH. Historically, specific water quality parameters, like dissolved oxygen level and total suspended solids, were monitored using manual, “static” tests in a lab, which causes a delay in any control feedback loop. However, these types of tests are gradually being replaced where possible with submerged probes that offer real-time continuous monitoring.
These specialized probes can be combined with a data logger that reads the output of the probe, for example one that measures 0-10 V or 4-20 mA electrical signals. This allows the water treatment plant operator to take advantage of the full set of capabilities of modern data loggers, including remote data upload, customized alarms, and other higher level logging functions.
Conclusions
Let’s return to our initial question: What are data loggers used for? The answer is that they have a wide diversity of applications, from manufacturing and other industrial processes, to transportation and distribution, to agriculture.
In all of these settings, data loggers are an efficient, automated solution for monitoring vital parameters. Modern data loggers can be integrated into complex networks to provide real-time, continuous, and remote access to data.