Model 3020T

Process Trace Oxygen Analyzer​​​​


The Model 3020T is a microprocessor-based instrument for detecting oxygen at the parts-per-million (ppm) level in a variety of gases. This instrument serves as the explosion-proof, bulkhead-mount version of the 3000 Series. Simple menu choices, externally accessible command switches, and dual LCD and LED displays make setup and operation clear and quick.

Analysis Ranges

Three user-configurable ranges are standard, with an excellent linearity precluding the need to recalibrate when changing ranges. Two fully programmable concentration alarms satisfy nearly any requirement. All features offer a sophistication that assures years of service.


Two standard 0-1 VDC and two 4-20 mADC isolated outputs provide both concentration and range identification. A bi- directional RS-232 serial interface is incorporated to relay information to a host computer for remote monitoring of critical functions.


All controls and displays are available from outside the housing. The instrument has two simple operator controls. A digital meter, an alphanumeric display, and a sample flow meter give the operator constant feedback.


  • ​C      Integrally mounted cal/zero valves

  • V      Plumbed for vacuum service

  • F      Flame arrestors for Class 1, Div 1, Group C/D service

  • G     Flame arrestors for Class 1, Div 1, Group C/D service with cal valves

  • H     Flame arrestors for Group B (hydrogen) service

  • I       Flame arrestors for hydrogen service with cal valves

  • S      Stainless steel cell block​


  • An explosion proof NEMA 4/7 rated enclosure

  • 2-line alphanumeric display screen, driven by micro-processor electronics continuously prompting and informing the operator

  • High resolution, accurate readings of oxygen content from low ppm levels through 25%

  • Advanced Micro-fuel Cell designed for trace analysis, with a one year warranty and an expected life of two years

  • Versatile analysis over a wide range of applications

  • Microprocessor based electronics: 8-bit CMOS micro- processor with 32kB RAM and 128kB ROM

  • Three user-definable output ranges (from 0-10 ppm through 0-250,000 ppm) assuring a perfect match for the user’s process

  • Air-calibration range for convenient spanning at 20.9%

  • Auto-ranging automatically selects the proper preset range for a given measurement. Manual override allows the user to lock onto a specific range of interest

  • Two adjustable concentration alarms and a system failure alarm

  • Extensive self-diagnostic testing at start-up and on demand with continuous power-supply monitoring

  • Two way RS-232 serial digital port for use with a computer or other digital communication device

  • Four analog outputs; two for measurement (0-1 VDC and isolated 4-20 mADC) and two for range identification

  • NEC and ATEX rated configurations



​3 Customer programmable ranges (min. 0-10 ppm) with auto-ranging
Calibration: 0-25%


​± 2% of FS at a constant​ temperature
± 5% of FS over operating temperature (once temperature equilibrium has been reached; except 0-10 ppm scale which is at ± 1 ppm)


0.5% of FS

​Response Time

​90% of FS 77°F (25°C) in less than 65 seconds


​32° to 122°F (0° to 50°C)


Signal:           Analytical measurement 0-1 VDC and 4-20 mADC (isolated)
Range ID:      0-1 VDC and 4-20 mADC (isolated)


​Analysis:       5 digit red LED, 3/5" high numerals
Menu:            20 character, 2 line LCD
Data Lines:   Bi-directional RS-232C serial interface, baud rate 2400 (remote monitoring of                              all critical functions)


​One system failure alarm contact to detect power failure
Two fully programmable concentration alarm set points and corresponding Form C 3 amp contacts


​115 to 230 VAC, 50/60 Hz


​Teledyne Micro-Fuel Cell, Class L-2
(2 year life expectancy with most applications)


Explosion proof enclosure is U/L and CSA listed for Class 1, Div 1, Group B, C & D service NEMA 4/7 rated

(for NEC version)

​25.63"H x 15.25"W x 11"D
(65.10 x 38.74 x 27.94 cm)


  • Monitoring inert gas blanketing​

  • Air separation and Liquefaction

  • Chemical reaction monitoring

  • Semiconductor manufacturing

  • Petrochemical process control

  • Quality assurance