I was in a shop this week for PQR testing per Claus 5 of the 2015 D1.5 (Bridge Code) and wanted to share some of that experience for anyone that might benefit. 

There is a great little app called "Welding Inspector's Stopwatch."  I paid $5 for it from the Apple App Store and it was very well worth it.  You just plug in the voltage, current, length of weld/test plate and then hit the 'start' button right when the welder starts welding and hit the button again when she/he stops.  They you hit the 'calculate' button and you instantly have your heat input for that pass to record on your pqr.  It also has calculators that you can use to see how changing current, voltage, weld length or time will change the heat input.  It's an outstanding app.

The first day of testing didn't go well - heat input was too scattered.  The welder was highly skilled and I could tell that he took it kind of hard that the test didn't work out so I suggested that maybe they practice with some scrap of the same length as the test pieces and have someone there to assist with timing/travel speed. So they marked off the steel in increments for the welder to see and he had an assistant call out the time in 5 second increments.  The next day I came back and we tested again and the welder was able to complete all 16 passes with no individual pass deviating from the average by more than 6%.

Hope this helps!