The O2E2 oxygen process analyzer utilizes Oxigraf’s proven laser absorption spectroscopy oxygen sensor to measure oxygen content in dust and particle atmospheres. With two (2) redundant channels of pre-stage filtering for “ping-pong” sampling and back-flush purging of lines to ensure sample continuity during purging and prolongs filter life. The model O2E2 measures oxygen content from 2-100% or 0 -100% optionally using our serial locking cell technology. The O2E2 has pre-filters of 5µm and 0.3µm.
Unit of Measure

Tunable Diode Laser Spectroscopy

N/A The Oxigraf is the next generation oxygen safety sensor. Laser diode absorption spectroscopy assures stable, long-life oxygen measurement: there are no electrochemical cells to replace or paramagnetic sensors to recalibrate. The laser diode, derived from high reliability telecommunications VCSEL (vertical cavity surface emitting laser) diode technology, is rated for more than 500,000 hours mean time to failure. The laser diode is thermally and electronically tuned to measure the absorption of oxygen at 763 nm, and also periodically measures the background to provide an automated zero. Pressure and temperature corrections are made to yield the correct oxygen concentration as the weather changes.

Fast Response

N/A Industrial processes need fast measurement of oxygen and timely update of operating conditions. The Oxigraf oxygen sensor responds in less than a second. The transit time of the gas sample through the sampling tube may be 1 second per meter of sampling tube. To respond within 5 seconds, a monitor with a 1 second response time would need to be placed within 4 meters of the potential hazard. Electrochemical sensors may require 20 or more seconds to respond to large, abrupt changes in oxygen concentration.

Side-stream Sampling


A two-stage diaphragm pump circulates a sample from the process. A small sample is diverted for measurement by the oxygen analyzer. Particle filters block contamination; a flow sensor initiates an inert gas blowback purge when necessary.

The O2E2 model adds a redundant input channel with "ping-pong" sampling and purging of lines to ensures sampling continuity during purging and prolongs life of filters.

Two Stage Filtration with programmable filter back-flush.


The Oxigraf O2E is our first generation of particle process and dust conveyance monitoring. To keep the analyzer from being contaminated by the process dust, Oxigraf uses a two-stage filter the filters are back-flushed periodically or when sample flow restriction is detected. The model O2E has two (2) pre-filters of 2 µm and 0.1 µm.

The Oxigraf O2E2 is the next generation process monitor for dust conveyance. To keep the analyzer from being contaminated by the process dust, Oxigraf uses a two-stage filter. Each filter is independently back-flushed while your gas sampling continues. No interruption of monitoring for periodic filter purge. The O2E2 has pre-filters of 5µm and 0.3µm.

Sample Flow Monitor

N/A The Model O2E/E2 includes a sampling pump, hydrophobic filter, and flow sensor. Any flow blockage or pump failure is reported as a low flow fault Warning and initiates a back-flush sequence. The set point for flow restriction is user adjustable. Status of the flow is reported via the communication port, and a warning condition is triggered as well. Thus remote monitoring of the flow system is enabled.

Temperature, Pressure and Humidity

N/A Temperature and pressure corrections are important. The Oxigraf sensor is corrected to within ±0.2 % over pressure changes of 50% and temperature changes from 0 to 50ºC. An oxygen sensor that only measures oxygen partial pressure instead of concentration, would report an oxygen variation of 2% with a 10% variation in barometric pressure. Humidity changes can also change the oxygen dilution caused by humidity, and the Oxigraf sensor is not corrected for humidity. A hot, wet day relative humidity of 50% at 37ºC (99ºF) corresponds to an absolute humidity of 3.2%. Such a water vapor dilution causes a variation from the cold, dry air oxygen concentration of 20.9% to 20.2%, a change of 0.7%.

Remote Display and Remote Maintenance

N/A Remote Display The Oxigraf Safety Monitor includes various communication outputs. A 4-20 mA current output may be programmed to relate oxygen concentration. The Horn-Strobe/Alarm relay may be enabled by a programmable combination of the two independent high/low alarm settings, the System OK/Fault or the operation Warning information. Up to five relays are available to denote System OK, various Warning states, two independent high/low alarms, and a general alarm.

Insensitivity to Movement

N/A The Oxigraf technology has no moving parts, in contrast to paramagnetic technology. Laser diode technology will have no false alarms due to equipment vibration and is transportable.

Code Access

N/A Control of the unit via the 12-key capacitive-touch panel can be restricted by use of a password. This permits access control for maintenance and unit calibration. Remote operation is also available via the RS-232 and RS-485 digital communications links.

Five Relay Option

N/A Five relays to denote Alarm, System OK, fault Warning, Limit A and Limit B. Fused terminal block for 24 V remote devices. RS232 and RS485 enabled with Remote Software Interface Guide. OxiSoft Software application is also available.

Enclosure Purge Indicator

N/A Converts the NEMA 4X "weatherproof" safe area enclosure to a Class 1 Div 2 hazardous area enclosure by using Type Z purging, monitoring a nitrogen or compressed air positive pressure in the enclosure. Customer seals the enclosure, supplies the purge/inerting gas, and initiates the purge before applying power.

Single-point Auto-calibration

N/A The process monitor comes with one (1) gas auto-calibration built-in and is under user program control.



N/A 0-100% Oxygen Range with advanced serial locking cell sensor Remote Indicators Two (2) point auto-calibration


Measurement Range

N/A 0-100% optional 2 to 100% oxygen


N/A ±0.5%

Cross Sensitivity

N/A ±0.2% for any foreign gas

Response Time

N/A <1 second at normal flow rate, additional low pass filtering programmable

Ambient temperature Operating

N/A -10 to 50 ºC

Ambient Temperature Storage

N/A -20 to 60 ºC

Gas Inlet Temperature

N/A -10 to 50 ºC

Gas Pressure

N/A 250 to 1150 mbar


N/A 0 to 95% non-condensing

Warm-up for Full Accuracy

N/A 5 min

Display Resolution

N/A 0.1% O2

Analog Output

N/A 4 to 20 mA (max 750 ohm load), range programmable

Serial Outputs

N/A RS232 (TXD, RXD, Ground), RS485 Modbus compatible


N/A Alarm Relay programmable in 12 different Horn/Strobe modes Limit Relay A: Programmable low limit or high limit, failsafe on/off Limit Relay B: Programmable low limit or high limit, failsafe on/off Low Flow Warning Relay: Active if sample flow problem SPDT, 5 Amps max, 115 VAC or 24 VDC System OK Relay: Programmable failsafe on/off


N/A 115 VAC 40 Watts max


N/A 16 x 2 character VFD 8 mm character size


N/A 12 capacitive touch keys


N/A Conduit connection: ¾ EMT x2 supplied by user. NEMA 4X rated non-metallic boxes with Lexan windows, wall mounted. Outside dimensions: Height: 39", Width: 18", Depth: 12" Weight: 65 pounds.

Electrical Interface

N/A 4-20 mA: Terminal strip (+/-) Power: Terminal strip (115 VAC) Relays: Terminal strip (N.O., Common, N.C.) RS232 Serial: Terminal strip (IN, OUT) RS485 Modbus: Terminal strip (+/- IN, +/- OUT)

Pneumatic Interface

N/A A 2-stage pump draws a gas sample at a flow up to 5 l/min at atmospheric pressure. Two-stage inlet filters block condensate:. Inlet/outlet tubing: ¼” OD rigid tubing. Larger bore tubing will degrade time response. With ¼” OD tubing having a 0.193” ID, th

Field Replaceable

N/A Analyzer enclosure unbolts with four screws. Electrical connections are made to a terminal board. Modular filter system. Pneumatic connections: Stainless steel compression. Sensor door may be removed at hinge pins.