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      • Published 17 Jan 2023
      • Last Modified 29 Aug 2023
    • 12 min

    A Complete Guide to Data Loggers

    Our guide looks at data loggers, what they are, what they do, and the different types of data loggers available.

    Reviewed by Stephen Bettles, Technical Interaction Engineer (November 2020)

    Data loggers allow users to capture various types of information about a specific environment or process, often gathered remotely over an extended period of time. Dedicated data recording devices are most often used in applications where critical measurements need to be taken regularly and consistently.

    In this guide, we will consider the primary uses and advantages, exploring some of the more common professional applications. We will also take a brief look at how these instruments work, and which types are best suited to particular tasks and environments.

    What is a Data Logger?

    Data loggers (also known as dataloggers or data recorders) are found in all manner of research, analysis, performance and process monitoring applications. As a result of this, they are used across a broad range of industries. They are designed to capture and store high volumes of accurate and detailed measurement data, usually as a way to track important environmental parameters in a specific process, location, or time interval.

    The information is gathered via sensors or similar detection instruments that have been calibrated for sensitivity to certain environmental stimuli. These sensors can either be built directly into the device as fixed internal components or attached externally when needed.

    Today, the majority of these loggers are battery-powered, compact and highly portable pieces of technology that form a key part of the wider data acquisition field. They can be used in almost any setting and are generally seen as a convenient and robust modern update for older, less flexible data collection equipment such as chart recorders.

    Data Logging Definition

    Datalogging is the process of collecting data over a period of time. It covers an extensive range of activities, purposes and environments.

    Data Logger Definition

    A data logger is typically a small but powerful piece of autonomous electronic measurement equipment. They are widely used in a diverse range of professional data sampling and analysis tasks.

    Advantages of Data Loggers

    There are many benefits when used out in the field across a variety of demanding applications, environments and industries. Some of the most useful data logger advantages and abilities include:

    • They offer a practical way to gather large volumes of performance, environmental or process data over time
    • As well as making for much more meaningful and usable data sets, this can also be extremely important in identifying or demonstrating patterns of behaviour or performance retrospectively
    • Due to their compact size and often rugged outer construction, certain models can be deployed in a wide variety of challenging and remote locations and left to record measurements automatically at set intervals for as long as they remain powered on
    • Processes and conditions can be measured, documented, analysed and validated across far more extensive timeframes than would be practical (or cost-effective) with constant supervision or input
    • Although often connected to a desktop computer at a later stage for data download, graphing, analysis and storage, they don’t need to be hooked up to any other devices while collecting measurement data
    • They are far more versatile in terms of deployment (location and duration) than devices that don’t offer any stand-alone functionality
    • Interfaces tend to be reasonably user-friendly; most instruments only need to be configured rather than programmed
    • Most general multi-channel data loggers can accept both analogue input channels (pH, temperature, humidity) and digital input signals (wind speed measured via a paddle, for example). Other types might be configured for a single specific type of thermocouple or atmospheric sensor
    • Low power consumption modes are common, allowing for reliable use for a very long time between battery changes or charges
    • Multiple price brackets are on offer, dependent on your budget and data collection requirements. Options range from relatively cheap and easy-to-use plug-and-play units up to extremely accurate and feature-rich high-end models with full wireless networking capabilities
    • Advanced features such as cloud-based Wi-Fi data logging can handle large volumes of information upload automatically and remotely, making real-time results globally available almost instantly (regardless of where data is being captured from)
    • Different sensors, accessories, add-ons and instruments can increase flexibility without necessarily having to choose a single dedicated acquisition unit for every type of parameter being measured and logged

    Data Logger Applications

    Examples of typical laboratory, field, and industrial data logging applications include:

    • Weather tracking, prediction and environmental hazard detection - data loggers are widely used in all sorts of environmental research and for tracking phenomena such as weather patterns, climate change, river levels/cleanliness, and numerous parameters of natural habitats and ecosystems
    • Pressure, temperature and flow rate recording - vital parameters in many industrial processes, storage facilities, energy plants, tank systems, production lines, and so on
    • Condition monitoring in medical and pharmaceutical facilities
    • Countless pharmaceutical and environmental control uses such as sterilisation, refrigeration, storage and cultivation
    • Agricultural and horticultural growth measuring and resource optimisation
    • Food preparation, storage, transport and display e.g. maintaining cold chain
    • Efficiency monitoring and facilities management - tracking power usage, monitoring heating and lighting provision in homes/offices/schools, HVAC and temperature control in warehousing and industrial units
    • Automotive and vehicular monitoring, performance and safety - crash data, road traffic counting and flow management, railway signalling performance, continuous emissions sensors, general automotive safety testing

    There are a great many reasons why particular jobs, roles or businesses might need to perform data logging activities such as those listed above. In addition to simply enhancing performance and efficiency across countless different sorts of processes, data acquisition is often closely related to issues of industrial regulation, health and safety monitoring, legal compliance and environmental/quality control.

    Additional data logging projects could include:

    • Sports, racing and performance analysis
    • Component performance tracking for troubleshooting and fault detection, including process monitoring for warranty conditions
    • General scientific/engineering research and recording purposes

    How Does a Data Logger Work?

    Most are equipped with an internal microprocessor (effectively a small, multi-function computer processing chip), some form of on-board data storage, one or more sensors or detection instruments, and potentially a variety of other accessories.

    A data logger works by automatically monitoring and recording specific environmental conditions and parameters via their sensor components, then storing the resulting data in their internal memory. They can be configured as either relatively simple single-channel devices or more complex multi-channel versions. These types will often have numerous sensors and accessories fitted for logging more diverse measurement ranges.

    View Data Logger Accessories

    These measurements are generally taken at regular intervals set by the user. Before placing the logger, you input some settings telling it how frequently to take a reading, and for how long. Depending on the application, a data logger might be configured to take just a single reading per hour or per day or as many as multiple readings per second. Once the required data has been collected, the electronic device will usually be able to show all of these captured measurements in a variety of handy formats, including visually displaying the results through graphs.

    As noted above, most modern variants of this equipment are small and battery-powered - especially the stand-alone variants. Typically, devices set to take less frequent readings will have the ability to enter a sleep mode between measurements, conserving battery power.

    Being compact and typically fairly rugged, they can often be left unobtrusively in the desired location for extended periods and don’t necessarily need to interface with a desktop computer. Modern variants can often output their captured data directly via a screen, although these tend to be somewhat basic. However, the data they collect is often downloaded to a computer or PC-based system for easier display, analysis, data transfer, and long-term archival storage.

    Types of Data Loggers

    In order to accompany the dozens of varying roles that these versatile devices can perform, a great many different types of data loggers are available. Just a few broad subtypes that you may already be familiar with include ‘black box’ flight and voyage data recorders, accident data recorders, remote weather stations, track and lap timers, and numerous sorts of vehicle sensors and on-board diagnostics (OBD) recorders.

    The most suitable data logging instruments and sensors for a particular scenario will be dependent on the types of measurements that you are looking to capture and analyse.

    Different brands or models might be designed to capture parameters related to all manner of data such as:

    • Humidity
    • Leaf wetness
    • Soil moisture
    • Air temperature
    • Time-of-use (motors, lights)
    • Water level and temperature
    • AC/DC current and voltage
    • Dissolved oxygen
    • Rainfall
    • Light intensity
    • Pulse signals
    • Wind speed and direction
    • Room occupancy
    • Differential pressure
    • Plug load

    Of course, these are just a few examples but the reality is that this equipment can be used to capture almost any measurable characteristic of an environment or process.

    Of the above, the most common and widely used types are temperature, pressure, humidity, voltage and current data loggers. Multi-input data loggers can measure signals from two or more of these input sources; certain advanced multi-channel models may even be able to sense and record all of the above.

    Temperature and Humidity Data Loggers

    It is thought that temperature is the second most-measured parameter the world over, after time. Unsurprisingly then, temperature data loggers are also one of the most frequently used measurement devices across all industries, and easily one of the most widely encountered data acquisition systems out in the field.

    Temperature data loggers (or temperature monitors) can often be used to measure both extremely high or low heats in both solids and liquids. Humidity (or, commonly, temperature and humidity) data loggers usually offer additional moisture-related capture capabilities such as dew point, absolute concentrations and relative humidity levels.

    There are numerous different designs, models and configurations of humidity and temperature monitoring devices, most of which use some type of internal thermistor or thermocouple. Additionally, they can often be connected to a variety of external sensors and temperature probe instruments, too. Depending on the exact use in question, certain industries and applications might require prior calibration to specific standards and protocols for compliance reasons.

    Data Loggers and Technology

    Take a look at this video and learn how PRO-MOTE data loggers record temperature and humidity to the cloud, which can then be accessed anywhere via different devices.

    Click the button below to browse temperature and humidity data loggers from our own RS Pro range.

    Take a Closer Look!

    Spotlight on the Pico TC-08 data logger, including how to use and set up the equipment, how to take measurements, how to record, take readings and share the data.

    Feeling inspired? Click the button below to find temperature data loggers from Pico Technology.

    Voltage Data Loggers

    Voltage loggers or electrical data loggers are another popular type and can again be bought in a wide variety of specialised configurations and models.

    Voltage data logging devices can usually adapt to any type of voltage measurement, including pressure to torque and load to force. Current loggers include a diverse array of AC and DC monitoring devices and are often used as a means of verifying construction or heavy plant equipment. These are widely chosen for tracking energy consumption and detecting drops and surges and can be bought in both single and multi-channel configurations.

    Other Types of Data Loggers

    Many other specific types of data loggers can be bought for performing more specialised industrial or domestic roles and functions, including:

    • Sound level monitoring
    • Water level measurement
    • Light intensity sensing
    • Shock and vibration control

    It is also important to be aware of broader categories, such as:

    Single input data loggers are generally set up to measure just one type of environmental parameter via a particular input type, source or sensor. They are often the cheapest and most straightforward.

    View Range

    Multi-channel loggers are complex yet versatile handheld devices designed to be carried between environments. They can accept various input signals via different types of probes, attachments and sensors.

    View Range

    USB data loggers are compact, low-cost units designed for PC compatibility via a standard port and USB interface. They are often cheaper than networked or wireless data loggers.

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    Is There a Difference Between Data Acquisition and Data Logging?

    Strictly speaking, yes - data logging is part of the broader data acquisition process. Acquisition involves the physical act of the actual collection of data, whereas logging specifically refers to the act of recording and storing that data. However, many modern types perform elements of both, which is why they’re so much more cost-effective and efficient than many older standards of data collecting and monitoring equipment.

    Why is a Data Logger Better Than a Thermometer?

    Most forms of data logging can be done manually using other types of measurement equipment. However, it’s often impractical, expensive (in human resources terms) and inaccurate to try to do this regularly over an extended period. Data loggers save both time and money by almost entirely automating the process. Additionally, they can also increase the accuracy both of the measurements themselves and the output data displays.

    What Factors Will Most Directly Influence My Choice of Data Logger?

    First and foremost, the primary influencing factors will be the exact type of data collection you need to perform and the purpose(s) for which the data is to be used. Additionally, you must also consider:

    • Cost
    • Size, weight, portability and mounting options (if applicable)
    • Battery life
    • Ease of use and configuration
    • Data export options and interfaces (including software and integration with any other relevant systems)
    • Build quality and environmental resistance (e.g. IP rating)

    You should also consider features and capabilities including:

    • Safe performance ranges (e.g. temperature, pressure etc)
    • Memory capacity
    • Accuracy and precision
    • Display resolution
    • Response time

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