Just as there are many different types of data loggers available, there are also many different types of data graphing and analysis software packages. In general, look for software that is Windows®- and MAC-based and highly intuitive so the learning curve is minimal. The software should enable you to quickly and easily perform tasks such as configuring parameters, launching the data logger, and offloading data, with point-and-click simplicity. Certain packages, such as Onset HOBOware® Pro software, allow you to batch-configure and readout hundreds of loggers very quickly.
The data logging software package should also offer powerful data plotting capabilities, with an ability to easily merge, append and crop data, and enable you to easily export data to other programs, such as Microsoft Excel, for analysis. For BLE-enabled monitoring, configuring the loggers and managing data simply requires downloading a free app to your mobile device.
When buying a data logger, make sure the product's enclosure is designed to withstand the conditions of the environment where it will be located. For example, if you plan to conduct monitoring in an office hallway, a hard plastic enclosure should suffice. If the data logger needs to work in a non-condensing environment, however, you would want to choose a product with a moisture-protective enclosure. It's also a good idea to ask about the availability of protective cases and other enclosure accessories for situations where increased durability and/or protection may be necessary.
Overall, data loggers are extremely low-power devices. However, because they are used in a variety of environmental conditions and sample at different rates, battery life can vary widely. As a general rule of thumb, make sure the data logger you select has a battery life of at least one year.
You may also want to ask your supplier about whether or not the data logger battery is user-replaceable, as this can eliminate the time and expense of having to ship the logger back to the manufacturer for battery replacement. Finally, data loggers that run off standard household batteries offer greater convenience than those requiring specialized batteries.
Cost of Ownership
The lower cost of microprocessors and sensors in recent years has helped push down the price of battery-powered data loggers. Although many data products available today are attractively priced, it’s important to look closely at the total cost of ownership before making your purchase. Here are some questions you may want to ask your potential supplier:
- Will the logger need to be calibrated by the manufacturer periodically, and if so, what are the cost implications over time?
- Will I need to invest in a pricey software package to analyze my results?
- Will I be able to use readily-available AA batteries, or will the logger require a proprietary or hard-to-find power source?
- Are cables included with the logger?
- Will I need to purchase a data plan for my web-based system, and if so, what types of plans are available?
Answers to these questions will help you understand the true cost of owning the data logger over the long term.
In general, data loggers should be easy to use, without requiring a great deal of technical assistance, even during the initial phases of use. Nevertheless, as with any high-tech product, there will always be questions. When evaluating data loggers, look for a supplier that offers a range of product support services. These services often start with a preliminary assessment of your application requirements and should include both telephone support and internet-based support resources.
It's also a good idea to find out if the supplier has the track record and financial stability to maintain the role of a long-term solutions provider. Then you can be assured that the company will be there to meet your future data logging requirements. Finally, you may want to ask the supplier for application notes and other references to gain a sense for how the data loggers performed in applications similar to yours.