Canada uses FT2s quite a bit and has generally be very happy with them. I don’t have any failure rates to share but we have documented a few types of failure on our internal wiki that I’ll share below.
1. Flowtracker (FT) 2 freezing/locking up
As per the latest RHC it is recommended to update to firmware 1.7 found in the software center. Special thanks to @Kris Assels (Unlicensed)
UPDATE: 2023-03-22 Information provided by USGS HaWG
Cause 1: This occurs with holding down a button and pressing another button before releasing the first would lock up the keypad
Fix 1: Install software version 1.7 or greater
Cause 2: The capacitors plus the solder would exceed the tolerance stachup and would result in the Torodex board flexing. The issue does not impact all FlowTracker2, since the solder height would vary during assembly.
Fix 2: The issue was resolved by using a smaller capacitor. SonTek will replace the main board at no charge.
2. FlowTracker2 – Low or zero SNR readings due to loose transformer wires
SonTek has determined that vibrations (in high water velocity conditions or during transport) of the FlowTracker 2 probes were resulting in the transformer wires breaking. A wire breaking on the transformer would result in low or zero SNR readings. As shown below (BEFORE picture, Figure 1) the transformers sits on top of the boards and any movement would/could cause this issue to occur.
To fix this issue, SonTek engineers had made the following changes to their production process:
Secured the transformer to the board using heat shrink as shown on the AFTER picture below (Figure 2).
Changed the wire stripping process for the transformer. The supplier was using a mechanical stripper to remove the plastic insulation. This was causing cuts in the conductor which would contribute to the wire breaking. The supplier now uses a thermal stripper to prevent this issue from occurring.
These changes were implemented in at the end of October, 2020. FlowTracker 2’s have serial numbers based on the year and week, so you can to check to confirm your FlowTracker2 probe has the fix already.
Any probe built after week 40 in 2020, will have the fix implemented.
FT2P2040001 was built in 2020 the 40th week.
If the serial number is FT2P2101003. It was built in 2021 week 01 and it would have the fix in place.
If the serial number is FT2P1923005; it would not have the fix installed unless it had been returned to SonTek for repair after October 2020.
For those units that have not yet fixed, Hoskins has offered a preventative repairs to avoid problems in the field. We recommend contacting Hoskin and requesting an RMA. Costs for these repairs are to be covered by Hoskin and SonTek YSI. NHS pays shipment to Hoskins.