Testing and Kit Features Analytical Chemists Instant Air Check Kit  Drager Aerotest Simultan
Low minimum pressure for testing (as low as 5 psi) Yes  No
Maximum Pressure tolerated Up to 6,000 psi 4,000 psi
Large bore to capture all particulate Yes No
Regulator-free kit Yes No
Wideband flow rate test range 2 SCFM to >20 SCFM Regulated 0.2 - 4 liters/min
Number of simultaneous compound tests >50 4
SCUBA and SCBA  Adapters Included Yes No
Built-in Safety pressure relief up to 6,000 psi Yes No
Ability to perform Particulate tests  (CGA Test L, D, E) Yes No
Oxygen Compatible Air Check Yes No
Ability to sample an empty SCUBA flasks  Yes No
Small portable testing kit Yes Yes
On demand laboratory consultation with chemists Yes No
Ability to test multiple specifications from a single sample Yes No
Ability to test gas purity Yes No

There are about 3 companies in the US that make air testing kits for checking compressed air systems. The differences between the kits made by each company are numerous and serious: the number of contaminants that can be tested at one time, pressure control methods, complexity of use, quality of technical support, and cost. Only the kits made by the Drager Corporation, and Analytical Chemists, Inc. (ACI) have the ability to test at least 4 contaminants simultaneously in compressed air, however, the two companies are dramatically different in other capabilities.

What is an Instant Air Check Kit, and is it better or cheaper than lab analyses?

An Instant Air Check Kit ©  is an air sampling kit that can pull a compressed air sample and test that sample on-site for selected contaminants.  At this writing, the sampling kits that fall into this category are either based on battery powered electronic meters with a pump and specific sensors, or color indicator tubes. The latter is the non-electronic, more universal,  least expensive and most popular approach. 

Better? There is nothing better or more thorough in checking air purity than a laboratory analysis.  Although color indicator tubes are available for many compounds, they cannot test for everything. Their results are generally sufficient in sensitivity, but are not precise nor as certain as a lab analysis..  There are, however, situations when distance and  timing are overwhelming factors.   For example, cruise ships or live- aboard boats are seldom near a port that can provide analytical services.  The same is true for many islands that have operations which rely on sending air samples to the U.S. to determine if the air is good or not.  And then, of course, what does a store or boat owner do when it suspects that the air contains a contaminant such as oil mist, or has to investigate a diver's complaint without a laboratory.  With an Instant Air Check kit, one can immediately test the air for the most common contaminants instead of sending a sample to a lab and waiting for the answer.

Cheaper? Maybe. The cost of the kits (a one time purchase of hardware) plus the cost of buying more supplies (color indicator tubes and filters) is more expensive than the typical lab fees for just the analysis.  However, when the shipping cost, taxes, and duty fees added to off-shore locations, those total fees can become  much higher than the actual analytical fees.  Despite that, if you factor in time, convenience, logistics and confidence, for off-shore use, the self-test kits are a bargain.

Comparison of Self-test Compressed Air Sampling kits.

Although there are about 5 companies offering color indicator tubes in the U.S., there are currently only 3  companies that make self-test kits: Sensidyne, Gastech, Drager and ACI (Analytical Chemists, Inc.)  The Sensidyne and Gastech devices are simple and inexpensive, but can test for only one compound at a time.  Moreover, their capability is limited, and they are tedious to use.   Moreover, their designs do not meet current Navy, NFPA or ISO1873 sampling criteria.  The Drager corporation has at least 4 different  compressed air sampling kits which allow a wider range of tests, but they also do not meet the wider scope of all Navy or NFPA requirements.  The final player, ACI uses Drager color indicator tubes plus membrane filters and variable air handling capability to make it the only technically correct universal air sampling kit available in the industry.  When combined with lab support and lab accreditation, the ACI kit meets all Navy, CGA, NFPA and ISO 1873 requiements.  A statement that sweeping requires a closer look a the two manufacturers:  Drager and ACI.

The most well known self-test kits are made by the Drager Corporation.   Drager offers an AEROTEST SIMULTAN kit for use with HP air, another for use with LP air, and a third kit for pharmaceutical/instrument air.  The down side is that their HP and LP kits are not interchangeable. Therefore, if you work with both low pressure and high pressure systems, you would need to purchase both Simultan kits.  Both current versions contain a pressure reducer and a flow controlled holder for 4 indicator tubes: CO, CO2, Moisture and Oil mist.  Drager also offers a low pressure test kit just for the pharmaceutical industry which can test up to 7 analytes simultaneously.  

In contrast, a single ACI Instant Air Analysis kits can sample HP, LP and Pharmaceutical systems.  Moreover, the ACI Instant Air Analysis kit can detect particulate and sample up to 10 analytes instead of only 7.   Particulate contamination is an important issue, but the Drager kits cannot test for particulate. 

The Instant Air Analysis Kits© made by ACI, also use Drager tubes as the analyte detector plus a membrane filter to collect oil mist plus particulate.  The patented design of air flow control and dual fail-safe pressure release in the Universal kit allows safe sampling and testing of both low as well as high pressure systems.   The kit uses adapters to sample an unlimited variety of air systems.  The occasional need for lab analysis is met with small self-purging canisters (300 ml capacity).  The kit simultaneously samples up to 10 Drager tubes, one of which concentrates airborne hydrocarbons for off-site lab analysis by GCMS.   And it does this in only 5 minutes.

Additional Considerations

Drager tubes are not perfect, and for this reason we include a canister and  pre-weighed filters.  As mentioned above, the bulk air canisters provide a way for you to submit an air sample for a laboratory analysis.  The filters let you see any oil mist or particulate in the compressed air stream, and because they are pre-weighed, they too can be sent to a laboratory for analysis.