As-found / as-left PID constants
A commissioning packet does not want a story of every photograph. It wants two columns: the numbers on the faceplate when you started, and the numbers you left in the controller. Those are as-found and as-left.
PIDSnap already stores every typed change on the session. The download from a completed tuning session is that record: plant units, empty sign-off lines, and a disclaimer that it is not a site SAT procedure. If the trend was mechanical — stiction, backlash, a saturated output — you get an evidence pack instead. Tuning constants are the wrong paper for a sticky valve.
As-found is the faceplate at the first change
As-found is the value the session started from, in the units on that controller: gain or proportional band, reset as minutes per repeat or seconds per repeat, rate in minutes or seconds. It is the first from-value PIDSnap told you to leave behind, not a reconstruction from a process model and not a number invented after the fact.
If a term was never moved, as-found and as-left are the same. A session that never instructed a change still produces the sheet, with both columns equal and a caption that says so. Do not fill the blank with a calculated Lambda or Ziegler-Nichols result. Those belong on the free calculator, not on this record.
As-left is the last number you typed
As-left is the last to-value stored on the session for that term. If you raised gain twice, as-found is the original and as-left is the second target. The step list under the table still shows each move, because a planner sometimes needs the path, not only the ends.
The loop row in PIDSnap is not updated by those instructions. The sheet therefore does not read current loop.gain and call it as-left. That would be a lie the first time anyone edited the loop form after the session closed.
This is not a site SAT certificate
Plants have their own SAT forms, witness lists, and MOC numbers. PIDSnap prints empty lines for technician, witness, date, and work order so you can attach the page to that procedure. It does not claim ISA, IEC, or vendor compliance. It does not guarantee the loop will hold through the next feed cut.
Everything on the sheet is informational. You remain responsible for the change, the permit, and the process. If the signature was mechanical, do not file an as-found / as-left sheet as if the constants fixed the valve. File the evidence pack with the work order instead.
Questions that come up
Where do I get the PDF?
Complete a guided session on a loop. When the session ends and the trend was not mechanical, the session page offers Generate as-found / as-left. Sign in from /register?next=/app, add the plant and the loop, and run the session. A free pre-flight check at /check does not produce this sheet.
Why is there no pass / fail box?
PIDSnap does not know your site's pass criteria. The outcome line is what the session recorded: resolved, improved, unchanged, or abandoned. Inventing a tick box would be a compliance claim.
Related
Start a guided session Or run a free pre-flight check
Last reviewed 2026-10-04.