Starting at $2,900.00

Not in stock. Usually ships in 3-4 weeks [?]

Need Help? Call a Temperature Engineer 1-800-884-4967

We're open Mo-Th 8am to 5:30pm. Fr 8am to 5pm ET


  • IN-SITU real time analysis for O2 and COe
  • Zirconium dioxide O2 sensor
  • Measuring ranges:
    • O2: 0.1 to 25.0% Vol
    • COe: 0 to 1,000 ppm (option combustibles measurement)
  • Accuracy:
    • O2: ±0.2% or ±5%, whichever is larger
    • COe: ±50 ppm or ±10%, whichever is larger
  • Die cast aluminum enclosure
  • IP65 protection class
  • Standard ANSI flange
  • Clean combustion

The MRU OMS 420 O2 & COe Transmitter provides real time IN-SITU analysis for O2 and COe measurements. The OMS 420 measures O2 from 0.1 to 25% and COe from 0 to 1000 ppm. No reference air is needed for operation. The OMS 420 provides easy removal and replacement onsite without removing the probe from the stack. The aluminum enclosure contains the electronics display and keyboard.

Required Components

These additional components are required for the operation of your product. We strongly advise you to purchase these components unless you already own them or own a suitable alternative.

MRU OMS 420 Probes
316Ti stainless steel DN65 PN6 flange and Inconel steel DN65 PN6 flange models


Please consider these optional accessories.

COe sensor for measurement of combustibles (equivalent CO) up to 1000ppm by using special heated solid electrolyte sensor
MRU PU420 Pneumatic Auto Calibration
For automatic calibration using permanently attached calibration gas cylinder
MRU 61494 Seal Gasket
Seal gasket for mounting flange ANSI150
MRU 52556 Seal Gasket
Seal gasket for mounting flange DN65
MRU Steel mash filter
Steel mash filter 35 x 2 mm, CrNi steel
MRU 56912 Locking Plug
Locking plug for calibration inlet port
MRU 61399 Solenoid valve
Solenoid valve (back purge)
MRU 59528 Replacement O2 Sensor
Replacement O2 Sensor for the OMS 420
MRU 62010 Replacement COe Sensor
Replacement COe Sensor for the OMS 420
MRU OMS 420 High Temperature Probes
Only for use with OMS420HT model, or use at very high temperature combustion sites
MRU 63607M Adapter Flange
For use above DN65 style sampling tubes at sites with 4" ANSI 150lbs flanges
MRU 63471 Special Cable
30m (90') special cable replacement of standard 10m special cable of models OMS420RT or OMS420HT