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MSA Orion VS Crowcon's Tetra

A side by side comparison between MSA Orion and Crowcon Tetra provides insight into the best available portable multi-gas detector for your requirements...

When shopping for a portable gas monitor, there may not seem to be many differences at first glance.  A more extensive comparison reveals a number of differences between MSA Orion and what we have found to be the superior multigas monitor, Crowcon Tetra. Example's would be the Orion unit requiring 2 button operation that is not very intuitive while Tetra features simple 1 button operation.  Tetra's internal software conforms to IEC 61508 standards while MSA Orion offers no such conformity or flexibility.

MSA Orion portable gas detector

Benefits of Tetra vs. MSA Orion...

First let's look at ruggedness.  MSA Orion casing meets Ingress Protection standards to IP54.  That's pretty good, but it's not a full outdoor specification.  Tetra meets standards of IP65, making it dust proof and water resistant to water projected from a nozzle.  This makes Tetra much more suited for harsh outdoor environments.

As far as ergonomics, Orion's design is rather tall and is bulky front to back, making it less convenient for personnel entering confined spaces and climbing ladders.  Tetra's compact, contoured design hugs the user's body providing ease of use and additional security.  MSA Orion has 2 displays on the front, 1 for concentrations and a second for diagnostics.  The Tetra goes two steps further by displaying all four gases simultaneously as well as diagnostics on the top of the unit where they are visible without removing the unit from where it is worn on the body.

The most important function of any gas detection device is the alarm.  Orion does not have a vibrating alarm.  Tetra provides a vibrating alarm as standard giving better and additional protection of gas hazards.  This feature is particularly useful in confined spaces where maneuverability is a concern.  Orion LEDs are located on the bottom of the unit.  When worn on a clip this impedes visibility.  Tetra's display and LED's are located on top of the device, making it easy to read without handling. Orion's visual alarm is red LED's only.  Tetra features a highly visible red-blue LED combination alarm.  Blue light photons have been proven to have greater visibility than red, which is why it is a standard flashing light color for emergency vehicles.

Orion's sensor capabilities are limited to flammable, oxygen, CO and H2S gases only.  The flexible Tetra provides a wide range of different sensor combinations that are fully  interchangeable and pre-calibrated. Orion does not respond to the presence of toluene.  Tetra's flammable sensor responds to aromatics, making it suitable for refineries and petrochemical plants.

Features of Tetra...

Tetra is designed with single button operation, flexible, intelligent sensor modules and shockproof internal construction that assures dependable gas detection in the most arduous environments.  Tetra gives extra protection from gas hazards with a loud audible alarm, piercingly bright dual red/blue visual alarm and an internal vibrating alarm.  Tetra's innovative design allows operating status to be viewed at a glance and has a 30 day countdown warning of when calibration is due.

Don't pay more for less...

Keep your operating expenses down buy purchasing the high quality Tetra that requires less maintenance  and optional parts than other models.  You can spend more for a portable multi-gas detector, but why?  Crowcon's Tetra is the most flexible, reliable and best priced gas detection instrument available.

Compare Features of Tetra with MSA Orion...
  Crowcon Tetra MSA Orion
Number of Sensors 1-4 4 Gas
Sensor Types Fl, OX, Toxics FL, OX, H2S, CO
Max number toxic gases 4 from total of 12 H2S and CO only
Intelligent Sensors Yes, fully pre-calibrated No
Size 124x128x57 mm 165x92x66 mm
Weight 500g 500g?
Ingress Protection IP65 IP54
Instantaneous Alarms 2 1, except oxygen Hi/Lo
TWA Alarms 8hr and 15min No
Alarm Tones Selectable from 5 Frequency Adjustable
Sounder Output 85dBA @ 1ft 85dBA @ 1ft
Visual Alarm Red and Blue LEDs on top Two LEDs visible 320
Vibrating Alarm Yes No
Confidence Flash Flashing Icon Flasing Icon
Confidence Sound Every 10 seconds Yes
Low Battery Alarm Yes Yes, 20 mins
Display Simultaneous Simultaneous
Display Type Graphic LCD LCD
Peak Display Capability On Demand Yes
TWA Toxic Display On Demand No
Auto zero on Start Up Configurable User Confirmation
Computer Interface IR PC Link
Data Logging Event Logging Optional
Flammable Gas Factors Yes No
Rechargeable Battery Li-ion NiMH
Operating Time 12hrs 20 hrs
Recharge Time 5 hours 3 hrs
Dry Cell Batteries AA cells AA Cells
Operating Time 15 hours 14 hours
Sampling Diffusion/Aspirator/Pumped Diffusion/Aspirator
Electric Pump Internal, optional Optional
Certification Code Rechargeable (Europe) EEx iad IIC T4 (Tamb +55degC) EEx iad IIC T3 (+40)
Certification Code Dry Cell (Europe) EEX iad IIC T3 (Tamb +55degC) EEx iad IIC T4 (+50)
Temperature Rating -20 to +55 degC -20 to +50 C
Certification Code Rechargeable (US) Class I Division 1 Groups A,B,C,D Class I Division 1 Groups A,B,C,D
Certification Code Dry Cell (US) Class I Division 1 Groups A,B,C,D Class I Division 1 Groups A,B,C,D
Rubber Boot Over molded No
Carry case Yes Yes
Chest Harness Yes Yes
Shoulder Strap Yes Yes


See the Crowcon Tetra Gas Monitor or read about all Portable Gas Detectors.

If you have any questions, call us toll free, we'll be glad to help!


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