When early versions of iOS 11 were released to beta testers, we discovered that changes to iOS prevented it from communicating with EMT 1 modules with serial numbers greater than 494. This manifested as a rapid series of messages showing that the module was being repeatedly connected and disconnected.
As of iOS version 11.2, these problems with iOS have been corrected, and all versions of the EMT hardware work correctly with the newest version of iOS on compatible devices. If you are seeing issues like the one described above, you are likely running iOS 11.0 or 11.1, and should update your device to the latest available version.
As soon as we confirmed this bug, we notified users via our mailing list. To join the mailing list and receive important notices about any of your equipment, use the sign-up form on our contact page. We also recommend registering your Echo Meter Touch module to be notified about any issues that may affect your model and serial number specifically. In the Echo Meter Touch app, open the Information page and tap "Register Ultrasonic Module."