This page deals specifically with problems encountered in a working isotope facility. Problems and troubleshooting tips should be related to isotope ratio mass spectrometers and front end devices associated with the IRMS.

General:

drying tubes:
nafion drying tubes: Low flow through drying tube, water builds up in mass spec. Nafion dirty or collapsed on itself. Clean or replace nafion tubing--see Repair Tips.
open splits:

SGE valves:

Bellows (thermo):
Bad potentiometers, specifically in newer (2008+)Thermo instruments that use ones with an aluminum collar around the shaft, Bourns 3590s. Those would stick, so instead of getting the full 10 turns for the bellows, you'd end up with a lot less. It could still register as 0 to 100%, but you'd have weird stuff like compressing from 100% to 50% would only increase pressure in the bellows 20%, not double it.
Installing the ones they used to use, the Bourns 3540s with the stainless steel collar, fixes the problems. They run ~ $25 each from your favorite electronic supply store (2010 pricing). See--Repair tips:

EA:
Costech ECS 4010:

Packing oxidation reactor:

Carlo Erba NC2500:
**rivernet.ncsu.edu/ sil/delta.html** (photo)

external image nc2500.jpg