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Zellweger Impact and Impact Pro vs. Tetra Gas
Monitor...
When maneuvering through confined spaces,
ergonomics become very important to the user's safety. Both Zellweger Impact
gas detectors have a four-button configuration
and a complex menu system that makes gas detection in the field a cumbersome
task. Tetra
features true single button operation with easy to see backlit graphic
display for readings and diagnostics. One good ergonomic feature
shared by the Zellweger Impact, Impact Pro and Crowcon Tetra is the top
reading display. This is the best configuration for field us.
Like a pager, the user can read the instrument by glancing down at it,
without removing it from where it is clipped to the person's body.
As far as sensors, the main point of a gas
detector, Zellweger Impact and Impact Pro leave something to be desired. Impact Pro
gas detectors are limited to a range of 8 toxic
gases. Tetra can interchangeably use the full range of toxic gas sensors making it
suitable for more applications. Furthermore, Impact gas sensor accuracy does not meet
some industry
required levels, making it unsuitable for many industrial applications.
Impact H2S sensor accuracy +/- 2.5ppm, cannot set alarm at 5ppm. CO sensor
accuracy for Impact and Impact Pro is +/-12.5ppm with poor accuracy for
30ppm alarm. Tetra's high quality toxic sensors alarm at industry required levels with
adequate accuracy. Zellweger Impact gas detectors require an annual cartridge replacement
while Tetra has a 2 year sensor life, reducing maintenance costs. When
it is time to change Zellweger Impact and Impact Pro sensors, we find the
attachment clips feel like they seat poorly and are
removed too easily, making them unsuitable for many industrial applications.
Zellweger Impact and Impact Pro flow heads are also difficult to fit and remove. Tetra's
sensors clip easily and securely. Simple attachment and removal of
accessories make Tetra user friendly and ultimately saves on maintenance costs.
Like most competitive portable gas detectors,
Impact and Impact Pro use a visual alarm that offers only red LEDs.
The Crowcon Tetra uses both red and blue LEDs. This provides higher
visibility due to the physical nature of the colored light frequency.
Blue light has a higher frequency, emits higher energy and is proven to be
brighter and more visible then red. Psychologically, red communicates
danger. For these reasons, emergency vehicles use either blue or both
blue and red flashing lights to get your attention, the same reason the
Tetra uses both blue and red for gas alarms.
Zellweger Impact and Impact Pro are also
outperformed by Crowcon Tetra when it comes to software. Impact gas
detectors offer no internal software conformity.
Tetra's internal software conforms to IEC 61508 standards, guaranteeing
software functional safety configuration of the instrument. The Tetra
software also features password protection, which the Impact and Impact Pro
do not.
Features of Tetra...
Tetra is one of the most rugged, reliable and
reasonably priced portable multi-gas detectors available. Tetra's
tough, innovative design allows for rough handling in harsh environments.
Compact and lightweight (about 1 pound) Tetra offers a wide variety of
features for a personal gas monitor. Tetra is certified valid for use
in temperatures up to 131°F, making it the perfect
instrument for use in foundries, steel mills and hot outdoor climates.
Why pay more for less?
When spending yours or your companies money,
don't you want the most features for the best price? Crowcon's Tetra
gives customers durability and flexibility while maintaining simple, 1
button operation. You can easily spend hundreds of dollars more on gas
detection instruments that offer less and are difficult and confusing to operate.
Get the most from your purchasing dollars with the high quality, easy to
use, cost
effective Tetra.
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Compare Features of Tetra with
Impact/Impact Pro |
|
|
Crowcon Tetra |
Zellweger Impact |
|
Number of Sensors |
1-4 |
1-4 |
|
Sensor Types |
Fl, OX, Toxics |
FL,Ox, and toxics |
|
Max number toxic gases |
4 from total of 12 |
2, from a total of
8 |
|
Intelligent Sensors |
Yes, fully
pre-calibrated |
No |
|
Size |
124x128x57 mm |
49x84x136 mm |
|
Weight |
500g |
560g |
|
Ingress Protection |
IP65 |
IP65/IP54 Sensor |
|
Instantaneous Alarms |
2 |
3 |
|
TWA Alarms |
8hr and 15min |
Yes |
|
Alarm Tones |
Selectable from 5 |
Two Tone |
|
Sounder Output |
85dBA @ 1ft |
5dBA @ 1m |
|
Visual Alarm |
Red and Blue LEDs
on top |
Rapid Red flashing
LED |
|
Vibrating Alarm |
Yes |
No |
|
Confidence Flash |
Flashing Icon |
Green LED |
|
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, Menu
Selectable |
|
TWA Toxic Display |
On Demand |
Yes, Menu
Selectable |
|
Auto zero on Start Up |
Configurable |
User Confirm |
|
Computer Interface |
IR |
Base Station |
|
Data Logging |
Event Logging |
Event logging |
|
Flammable Gas Factors |
Yes |
Yes |
|
Rechargeable Battery |
Li-ion |
NiMH |
|
Operating Time |
12hrs |
12hrs |
|
Recharge Time |
5 hours |
4 hrs |
|
Dry Cell Batteries |
AA cells |
Yes |
|
Operating Time |
15 hours |
20 hours |
|
Sampling |
Diffusion/Aspirator/Pumped |
Diffusion/Pumped |
|
Electric Pump |
Internal, optional |
Optional Internal |
|
Certification Code Rechargeable
(Europe) |
EEx iad IIC T4 (Tamb
+55degC) |
EEx iad IIC T4 |
|
Certification Code Dry Cell (Europe) |
EEX iad IIC T3 (Tamb
+55degC) |
N/A |
|
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 |
No |
|
Chest Harness |
Yes |
Yes |
|
Shoulder Strap |
Yes |
No |
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!
1-877-688-2703
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