Answers to frequently asked questions about data loggers.

What is a data logger?

Data loggers, or dataloggers, are electronic devices designed to collect and store specific or universal values, often independently of a PC. This way you can log data anywhere and then come back later to download readings to a computer via USB stick or cable. Many also support alarming capabilities to alert you whenever their user-set limits are exceeded. Data loggers are much more reliable and accurate than manual measurements and also free up workers for other duties.

They’re commonly used to solve a short- or long-term problem, for example when you need a way to alarm tank temperature or graph data to troubleshoot a faulty process. Data loggers are also utilized as general tools, including current/voltage dataloggers to identify energy savings areas or to monitor machines for signs of upcoming failures. Another main reason to use a datalogger is to gather and archive data for regulatory purposes whether it’s for a product, a piece of equipment, or environmental temperatures, say inside a surgery room or residence. Read a tutorial on the 5 ways a data logger can save you money.

Where are data loggers used?

Data loggers are used in all kinds of industries and for all kinds of applications. For example, agriculture and horticulture, temperature monitoring in storage and transportation of food; environmental monitoring both internal and external; laboratories and healthcare; automotive industry, energy measurement, quality assurance, research and more.

How are data loggers powered?

Most data loggers operate on batteries, but some models can also be powered externally. Usually data loggers consume very low power. You’ll want to note the battery life which varies considerably based on the manufacturer, model and how often it’s designed to take readings (sample rate).

Many data loggers have non-volatile memory which ensures that recorded data is still safe if the battery fails or power is lost. The logger’s software will usually tell you when the battery’s getting low. You can also choose a model with a user-replaceable battery.

How accurate are data loggers?

This depends on the model, but many data loggers are more than accurate enough to cover most applications. If you’re monitoring product or room temperature, a logger that’s accurate within a few degrees should be enough, which will keep the price low, but some applications benefit more from high-accuracy models accurate within one-tenths of a degree.

How many data loggers do I need?

This depends on the number of monitoring points you have, for instance how many areas you need to cover in a given room or on a product pallet. Data loggers are available in configurations with anywhere from one to hundreds of inputs.

How long can data loggers record?

Many data logger models are durable and will continue to reliably operate for at least a few years, although cold chain data loggers are available which do the job for a single trip and a low cost. Modern loggers can take a sample every second which is more than enough for most cold chain applications. Sample rate is inversely tied to battery life and the max sample rate depends on the logger chosen.

Recording duration depends on the memory capacity of the logger and the sample rate. Duration can be determined by dividing the memory capacity by the sample rate. For example if the logger can store 10,000 samples and you take 2 samples every minute, the logger could run for 10,000/2 or 5,000 minutes (about 3 days).

Where are alarms usually sent?

Local alarms can consist of anything from bright LED indicators and beeps to loggers with external alarm outputs. More sophisticated models will automatically send you an email or text alarm to your smartphone so you’re always on top of potentially critical changes in your product or process.

How do you retreive the data?

Many data loggers record data to a memory card or Flash stick for easy retrieval. More advanced models can also send the data automatically over Serial, Ethernet, or wireless communication (WiFi dataloggers, etc.). Users often make selections based on their facility’s wired or wireless setup.

Do you have to learn how to program?

For the average user the answer is no! Data loggers commonly use Windows-based control software for setup and configuration. Simply connect the logger to a PC, follow the configuration wizard and pick your sampling rate and start time—all this normally just takes a few mouse clicks. If you need a data logger for documentation purposes, it’s especially important to find software that can print out graphs and tables to show auditors proof of your best practices.

How much do data loggers usually cost?

When shopping for a data logger, you want to be sure that the device itself can do everything you need, including the right # of inputs to cover all your points, communication options and software. While most loggers are quite affordable, check to see if that includes everything--avoid paying extra for memory cards, communication modules or software.

Where can I buy a data logger?

You’ll find lots of data logger manufacturers and distributors online, so make sure you buy from a supplier offering free technical support. While data loggers are easy to use, you won’t get stuck if there’s a number you can call if you run into a problem, especially if you’re a first-time user.