35K0104R0, NOx Detector 0-800ppm CLD 200 cc/min, Replaces Rosemount 659754 and Tyco 1021326-100-TES

If you’ve stumbled on to this FAQ, you must have a Rosemount NGA-2000 CLD analyzer to measure NOX either dry or wet (referring to the WCLD version).   The detector portion of this analyzer is OEM p/n: 659754 (obsolete) and is sold by us under this part number:  35K0104R0.   It is the same OEM detector and fully compatible with your NGA-2000 or uCEMS.

I’d like to point out that this detector assembly is COMPLETELY repairable and should never be chucked in to the dumpster.  Here’s why:

  • If the capillary gets clogged … unclog it or solder in a new one
  • If the heaters fail open … replace the heaters
  • If the resettable fuse fails open … replace the fuse
  • If the barrier window gets cracked/busted … replace the window
  • If the temperature sensor goes bad … replace it
  • If the reaction chamber leaks … replace the bad seal (or both seals)
  • If a pin breaks off or a wire opens in the harness … fix the harness
  • If the metal barrel rusts through … this has never happened, but there’s always a first time … replace the housing
  • If the photosensor gets weak or dies completely … replace the sensor*          (* this is the most challenging aspect as the OEM wants about $8000 for this chip; and, most of the time, it’s the barrier window that gets clouded/stained from the ozone-NO reaction; we don’t change out very many sensor chips).
  • If the photosensor won’t cool down to 1°C, it might be a bad Peltier section of the chip -or- most likely, it’s a bad Darlington Pair power transistor (mounted on the aluminum divider panel).

We’ve been fixing about two of these per year for the past 20 years.  Don’t listen to the rumors that you can’t procure a NGA-2000 CLD detector assembly, we can get them or repair them.