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What Are Data Loggers?

data logger - weather station The name says it all – data loggers are data recorders, electronic devices that measure, record,  and log changes in conditions over a given period. The basic data logger is a compact, battery-powered unit featuring a removable data storage memory, onboard microprocessor, and a simple sensor.

By virtue of their capabilities, data loggers are at the core of most environment  monitoring systems. They are tasked with collecting, monitoring, and documenting critical environmental data, notably temperature, humidity, and pressure.

A data logger can work reliably as a standalone unit. But in practice, a monitoring system usually consists of a network of data loggers that work in concert and feed data to a centralized data processing system, such as a cloud-backed database. Organizations often use these devices to stay in compliance with regulatory requirements and ensure consistency in environmental conditions.

Read on to learn more about data loggers — how they work, what functions they perform, where they are used, and much more.

How Do Data Loggers Work?

The core role of data loggers in an environmental monitoring system is to ensure that critical machinery and locations are within preset limits. To do so, they consistently measure and document many different conditions to which products or equipment are subjected, ranging from storage facility temperature for vaccines or foodstuffs to voltage coursing through lathing machinery.

The main goal of using data loggers is to create a trail of validated and certifiable monitoring data, crucial for ensuring product safety, protecting valuable assets, and passing regulatory audits. Organizations can also use logged data to detect excursions in conditions and minimize inefficiencies in quality control monitoring, according to Dickson.

The core elements of a data logger include the memory component, the sensory input (or multiple inputs), the micro-processing unit, the power source, and the communication hardware.

It all starts with sensors, which measure conditions (e.g., temperature, voltage, pressure, humidity, etc.) and send the information to the microprocessor in the form of electrical impulses.

Sensors are categorized on the basis of what they measure:

Temperature sensors: Modern data loggers use many different temperature sensors, which can be prefabricated silicon-based IC sensors, thermistors, resistance temperature detectors (RTDs), and of course, thermocouples. They can collect and input a broad range of temperatures, from below solid freezing temperatures to blazing high gaseous temps.

Humidity sensors: Calibration rooms, autoclaves, greenhouses, warehouses, and other settings often need a specific relative humidity range to stay safe and ensure efficiency. These sensors feed data loggers with humidity readings over time with the spaces.

Pressure sensors: Also known as barometric sensors, these probes record the pressure of liquids and/or gases in an enclosed space. Thus, they help figure out altitude, gas flow, fluid speeds, and water levels, plus record air pressure in weather events like hurricanes.

To do their job well, barometric sensors are designed to stand up to extreme elements, like submergence in deep ocean water and exposure tohigh heat and harsh weather. There’s also a subset of pressure sensors that deal with absolute pressure.

Voltage/Current sensors: As the name suggests, these sensors help log voltage changes. On their end, current sensors measure the current flowing through a specific point on a circuit.

Vibration sensors: These sensors make a record of shocks and vibrations that a specified object, environment, or product is subjected to. They feed information to data loggers with built-in accelerometers to determine and record the intensity of tri-axial shocks and vibrations. Their primary aim is to help detect shock-based impacts.

Other data loggers are fitted with or wired to pH sensors, air quality sensors, CO2 sensors, contaminant sensors, pathogen sensors, radiation sensors, and even pulse sensors.

Recording the Data

iot - Internet of Things The electronic chip transforms electrical signals into data that you and the computer can understand. More advanced digital data loggers may provide alarm features, control buttons, and display screens where personnel can read data, change settings, and recalibrate the device.

Some data loggers use USB flash disks for data retrieval and storage, while others interface directly with a PC. The more modern versions allow for web-based access through a software interface. Part of the Internet of Things (IoT), they connect wirelessly, allowing monitoring managers to simply view and analyze the collected data in real-time from any internet-connected device.

What are the Applications of Data Loggers?

By now, you know that data loggers monitor and document many functional conditions, which makes them helpful for various applications that include:

  • Monitoring food temperature
  • Monitoring vaccine storage conditions in transit, on-site, or at clinical facilities
  • Keeping track of on-field plant growing conditions
  • Validating humidity and temperature levels of shipment and storage facilities
  • Providing property managers with information on air condition, ventilation, and central heating for optimizing energy-saving efforts

Data loggers can also be employed in industries where monitoring and documenting the environmental data are essential to safety, efficiency, and proper function. The following industries account for the most notable usage of data loggers:

Biopharmaceutical: Benefits of data loggers for the biopharma industry are unquestionable. They improve research and development, facilitate audit compliance, assure product quality, guarantee patient safety, and minimize operational costs. Overall, data loggers help biopharma firms realize long-term returns on their investments.

Food and Beverage: The shelf life of most farm produce and processed foods can be extended by storing them at specific temperature ranges. Data loggers are essential to monitoring and verifying the safe handling and transportation of products along the supply chain. Without consistent condition monitoring, contamination can occur, potentially resulting in widespread food recalls, public health crises, and expensive lawsuits.

Healthcare: With patient safety in mind, humidity, pressure, temperatures, and air quality must be monitored in hospitals and other healthcare settings at all times. Data loggers can also be used to maintain the efficacy and integrity of vaccines, medications, and life-sustaining medical equipment.

Manufacturing: Plants, factories, and other manufacturing facilities are subjected to many environmental factors that affect product quality and production efficiencies. These include gas/fluid pressure, temperatures, pressure, CO2 emissions, and the current flowing through machinery. Data loggers can help keep a close tab on all of these factors.

Aerospace: Operators and makers of missiles, helicopters, airplanes, and space stations must keep an eye on fluid pressures, gas pressures, shocks, and temperatures to which their equipment and precious cargo are exposed.


Data loggers are a vital piece of monitoring equipment. They are essential to the  environmental monitoring systems in multiple industries for consistency assurance, quality control, and regulatory compliance.