How Does a Data Logger Actually Work?

A data logger is exactly what it sounds like – an electronic chart recorder that’s responsible for monitoring and recording variations in conditions over time. The basic version is typically a small, battery-powered device with an inbuilt microprocessor and internal or removable memory for data storage, as well as a sensor.

Data loggers are the workhorses of environmental monitoring as they continuously gather and document data on environmental parameters such as relative humidity, temperature, voltage, current, and pressure. Highly specialized devices can keep track of air quality, microbial/pathogen contamination, and particle count, among others.

Integrated into a monitoring system, data loggers can comprise multiple channels working in concert or can be single, standalone units. They are prominently used in several industries where environmental monitoring is critical, including:


  Aerospace and aviation

  Food and beverage


  Pharmaceutical and vaccine production

  Third-party logistics (3PL)

  Medical devices

What are the Benefits of Using Data Loggers?

Accuracy, accountability, and transparency are critical success factors in highly-regulated industries like food and beverage, healthcare, and pharmaceuticals. These can be difficult to accomplish when organizations are also striving to keep up with volatile consumer demands, a rapidly changing regulatory landscape, and evolving technologies.

As part of a well-designed environmental monitoring program, data loggers can help address several of these pain points for industries. The benefits of environmental monitoring (using data loggers) include:

They help organizations save money in the long run. Advanced data loggers, like those in the are automated and connected to a cloud-based service featuring a beautiful, intuitive interface for monitoring data from any PC, tablet, or mobile device. These provide critical insights on time, free up employees to focus on what matters most, and reduce human errors, delivering high ROI for organizations in the long-term.

They improve product quality. Monitoring critical environmental data from the point of manufacture to the point of delivery ensures the product reaches the end-user in optimal quality.

They help organizations with regulatory and audit compliance. One of the most pressing pain points for healthcare, pharmaceutical, and medical device industries is staying on top of compliance and passing routine audits. Data loggers enable these industries to continuously monitor and log critical environmental data, which helps reduce the chances of non-compliance during audits.

They help organizations operate more efficiently. With automated, cloud-based monitoring systems, there’s no need for manual chart collection and monitoring, which significantly improves operational efficiency.

They enhance consumer safety. Since data loggers “log” essential environmental data continuously, organizations can ensure that their products are consistent throughout the entire supply chain. This guarantees that the products not only will be effective but also safe for the end-user.

They facilitate R&D efforts. In a Research & Development environment like a lab, the results of a study, trial, or experiment must be replicable. This is where data loggers can come in handy, especially in determining which exact conditions produced the best outcomes.

So, How Do They Work?

A data logger consists of at least three components:

a) A microprocessor – you can think of it as a small yet powerful computer.

b) A data storage unit – this can be an internal memory chip, a standard HD/SD drive, or both.

c) A sensor – it can be a single, standalone sensor, or several sensors feeding data to the same logger.

It all starts with the sensor, which can be either external (not part of the data logger) or inbuilt (integrated into the construction of the device). Sensors have one job: they collect and receive environmental information, meaning they take the actual temperature, pressure, or other parameters you intend to monitor.

According to Dickson, sensors can be either built-in or external. They come in all shapes and sizes, and each sensor usually measures only one parameter. In other words, you’ll find temperature sensors, pressure sensors, humidity sensors, carbon dioxide sensors, pH sensors, voltage sensors, and so forth. There is a specific sensor for every environmental condition out there.

The information received by the sensors will be handled or “processed” by the small computer (microprocessor). The processor takes signals, waveforms, and other types of information fed from the sensors and converts them into computer-readable data.

Generally, a logger can accept one or several different input data types. For example, a multi-input data logger can accept relative humidity, temperature, and pressure readings simultaneously from respective sensors. In fact, some state-of-the-art devices can accept all types of environmental data input.

The most common data input types accepted by data loggers include:

  Temperature – These data loggers can monitor and record an extremely long range of temperatures, including gas, liquid, and solid temperatures.

  Current – There are a variety of DC and AC loggers, most of which are used to monitor heating equipment.

  Voltage – These can monitor a range of voltage measurements, including load-to-force voltage, pressure-to-torque voltage, etc.

  Humidity – Humidity data loggers monitor changes in water vapor concentration, dew point, and relative humidity in metric or standard units.

  Pressure – Pressure loggers measure the pressure of liquids and gases, including water pressure and atmospheric pressure.

  Pulse – These data loggers monitor a myriad of pulses including electromagnetic vibrations, heart rate pulses, blood pressure pulses, heat pulses, etc.

  pH – These measures changes in the pH of liquids and gases.

  Air Quality – These monitor the levels of air components, including pollutants, CO2, allergens, particle count, and so forth. They usually take a small sample of air at equal intervals of, say, 1 minute, 5 minutes, 15 minutes, 30 minutes, 1 hour, and so on.

What happens to the logged data?

The recorded environmental data can be saved into a digital storage unit within the device, sent directly to a computer, or contained in a retrievable memory card, in which case you manually remove the card and transfer the data to a computer.

Depending on the kind of logger, you can use the device’s software interface to view the data, get insights, and even print it out. In advanced data loggers, the device is cloud-enabled, which means you can access the data in real-time using any computer, tablet, or mobile device.


Data loggers consist of a sensor that receives environmental information, a microprocessor that converts that info into readable data, and an internal/external memory that stores it.

Data loggers are a crucial component of a viable environmental monitoring system. These electronic devices monitor and log a range of environmental data, from temperature to CO2 levels, allowing organizations to detect out-range changes and correct anomalies promptly.

In addition to audit compliance, they also help with product quality, research accuracy, long-term ROI, consumer safety, and operational efficiency. 


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