A number of years ago, the team from Seritag created the ScanStrength NFC tag performance rating system to help customers select tags. The ScanStrength scale ran from 1 to 10 where 10 was the NFC tag with the furthest tag scan distance and 1 was the tag with the shortest. In 2019, Seritag launched the Real ScanStrength which now tests each tag with 12 of the most popular mobile phones and provides a actual average scan distance in mm.
Seritag use 12 different mobile phones selected from the current top sellers and a number of the past top sellers from recent years. We have built a custom rig which then approaches each NFC tag from various angles to mimic, as close as we can, real world usage. The average scan distance of each phone is then averaged across all mobile phones to provide a single distance in millimetres. This is a tags Real ScanStrength.
To keep Real ScanStrength up to date, we will refresh the mobile phone list once each year and then recalculate each tag's Real ScanStrength rating. The current list includes :
|Mobile Phone||Background Scan||App Scan|
|Google Pixel 3||Tested||-|
|Samsung Galaxy S7||Tested||-|
|Samsung Galaxy S9||Tested||-|
|Samsung Galaxy S10||Tested||-|
|Huawei P30 Pro||Tested||-|
|Sony Xperia 10||Tested||-|
|HTC One M7||Tested||-|
The iPhone testing is a little different. While Android phones can scan NFC tags in without opening an App, only the latest iPhone Xr, Xs and 11 have 'App free' tag scanning - also called background tag scanning. Therefore, the iPhone 8 can only be tested from within an NFC tag scanning App. Additionally, iPhones with background tag scanning (iPhone Xr, Xs and 11) have a slightly increased scan distance performance when scanning from within an App than using background tag scanning. Therefore, to get a better all-round rating, we test using both with an App and without an App.
NFC tags designed to work on both metal and non-metal surfaces have a barrier material between the tag and the metal-facing side. The way the barrier material works and the design of the tag itself can mean that scan distance performance on metal and non-metal surfaces can vary for the same tag. Therefore, for on-metal tags, we test both on metal and on non-metal (wood) and provide two Real ScanStrength ratings - the first is not on metal and the second is on metal.
It's clearly important to note that Real ScanStrength is an average and that there's often quite a bit of variance between phones. The purpose is to give you some indication what you might expect and importantly how one tag might compare to another. As with all things technical, we strongly advise you to understake testing to get the best indication of the scan distances you can expect for your project.