We carry several WiFi products and we’re often asked about their range. In other words, how far from the WiFi router can the data loggers be located? Unfortunately, this is like asking us to forecast the weather next Sunday. There are simply too many variables for us to predict how well any WiFi product will operate in all but the most clear cut cases. Beyond the distance between the data logger and the WiFi router, WiFi range is affected by the number of walls and floors that separate them, their construction, ambient levels of electromagnetic activity, electrical wiring density, and more.
None of this helps you arrive at an answer for the range question, but here are some ideas that may.
WiFi Range Audit
Why not discover the answer to the WiFi range question empirically? Given the proliferation of WiFi-enabled portable devices (most notably cell phones and tablet computers), try syncing such a device to your WiFi network, place it where you want to locate the WiFi data logger, and see how well it performs. Try downloading a large file to get a feel for the fidelity of the WiFi signal in your area of interest. If the download goes well, you have every reason to believe that a WiFi data logger will work equally well.
The Unintentional WiFi Faraday Cage
A Faraday cage is a metallic enclosure that impedes or inhibits electromagnetic energy. Radio devices placed inside such a cage occupy an RF dead zone. Unfortunately, many environments where customers need to make measurements are unintentional Faraday cages. I’m thinking of ovens, refrigerators, and freezers that are usually if not always constructed with a grounded metallic shell. Placing a WiFi product inside such an area may isolate it from the outside RF world. Again, use the WiFi Range audit suggestion above to predict performance in this situation. Start a large download, and then place the device inside the environment and close the door.
External WiFi Data Loggers
When an environment that you’d like to measure presents a Faraday cage-like dilemma, consider a probe-type data logger where the probe is placed in the monitored environment while the WiFi data logger remains outside. Many ovens, refrigerators, and freezers provide an instrument port for such a purpose, so you won’t have to drill holes in most cases.