SMARTEST MONITOR: ABLE TO MONITOR THE MOST CHEMICALS

The ACM uses the analytical technique of FTIR.
The analyzer constantly produces an infrared spectrum across the "fingerprint" region, from 2 to 25 microns, which is the same as 5000 to 400 wavenumbers (cm-1 ).
Since the spectrum has a high resolution, it is possible for the FTIR, with the aid of a computer, to separate the absorption peaks of different chemicals even if they are almost identical.

Nearly all gaseous chemicals absorb infrared radiation in the 2 to 25 micron region.
In fact only a very few do not. The gases that do not absorb are either
1) atomic gases, such as He, Ne, Ar, etc. or
2) diatomic-monopolar gas, such as O2, Cl2, N2, etc.
While these chemicals are not detectable by the ACM, all other chemicals are.
So, the ACM is able to monitor nearly any chemical in use now or in the future.

The ACM is set up for continuous and automatic air monitoring.
All of the air samples flow through a gas cell and the infrared beam of the FTIR passes through this gas to be absorbed the gases in the air sample.
The ACM is able to monitor any chemical that is in the gas (vapor) phase, except for the atomic and diatomic-monopolar gases.

MONITORS THE CHEMICALS USED IN SEMICONDUCTOR PROCESSES

A. Corrosive Gases: Nearly all ACMs are used to monitor corrosive gases such as: HCl, HF, HBr, NF3, NH3, WF6, BCl3, BF3, CCl4, SiCl4, SiF4 and SiH2Cl2.
Also monitored by the ACM is Cl2. Since the FTIR does not "see" Cl2, it is monitored by connecting Cl2 gas detectors to the ACM using 4-20 mA signals, one per gas detector.
In that way Cl2 can be added to any ACM point and reported by the ACM.

B. Organic Vapors: Any ACM can monitor the vapors of all organics used in a facility.
Organics most commonly monitored include: Acetic Acid, Alcohols (IPA and MeOH), PGMEA, EGMEA, Acetone, MEK, n-Butyl Acetate, Dichlorobenzene, Methylene Chloride, Ethyl Benzene, HMDS, Phenol Trichloroethane/ethylene, and Xylene.

C. Poisons, Flammables and Unclassified Gases: The ACM is used to detect gases in the general range of about 0.5 PPM to 500 PPM.
It is often used to monitor gases such as: NO, NO2, N2O, CO, CH4, SiH4, Freons and SF6.
For gases that are highly toxic with TLV's in the PPB range, such as AsH3, PH3 and B2H6, the TeloSense TGM is recommended, because it is more sensitive and faster.
But, the ACM will monitor AsH3, PH3 and B2H6 in the 0.5 - 500 PPM range, which is good for emission monitoring. Even H2 can be monitored at these points by interfacing H2 gas detectors to the ACM.

D. Monitors 15 Gases per Point: The high resolution infrared spectrum allows the ACM to monitor for as many as 15 gases on each sample point.
As it changes to the next sample point, it can monitor for 15 different gases and any combination of the gases: corrosive, organic, poisonous, flammable or unclassified.

STORED SPECTRA IDENTIFY UNKNOWNS AND INTERFERING GASES

The ACM has a unique feature known as Demand Scan.
At any time the user can select this by pressing “D” on the keyboard. Then, the ACM will stop scanning points and ask the user to enter the Demand Scan point.
Once entered, the ACM will scan that point, print the results, activate any alarms (if any gases exceeded an alarm limit concentration) and store the spectrum to the computer’s hard disk. The purpose of Demand Scan is to give the user a priority scan of any point where a there is an odor or suspected gas leak.

The ACM will immediately scan for the gases that have are normally monitored on that point.
But, maybe none of those gases are leaking. Maybe it is an unknown chemical that is getting into the air.
The information stored by the ACM is the complete infrared spectrum. This spectrum can be used at any time, even days or weeks later, to help identify the unknown chemical with the aid of Spectral Search Software and Spectral Libraries.
TeloSense will analyze a computer disk for the user using the stored spectra.

The ACM is also set up to automatically store the infrared spectrum every time there is an alarm.
With this information, the user or TeloSense can verify that any alarm is valid.
If it is caused by a foreign and interfering chemical, it will be easily identified in the spectrum.
TeloSense uses that to protect the ACM against future false alarms from that chemical.
Or, the chemical can be added and monitored by the ACM.

MONITORS ALL SAMPLING LOCATIONS

A. Gas Cabinets and Cylinder Storage Areas: All ACMs are used to monitor the sources of gas leaks. The ACM has programmable output relays that are used to automatically shut off gas cylinders.
Since it can identify the actual gas or gases leaking at any point, the ACM can shut down the specific gas cylinder that will stop the leak.

B. Process Furnaces (Tools): All ACMs are also used to detect gas leaks inside tools and in the exhaust ducts. If one tool has a leak, the ACM can shut down only the gases going to that tool.
This minimizes lost production time.

C. Breathing Zones: ACMs monitor the air in the worker’s environment to minimize exposure to chemicals of all types. This is especially useful in limiting the exposure to organic solvents.
(Note: The ACM is not used to monitor AsH3, PH3 or B2H6 in the workplace - it is not fast enough or sensitive enough for this use).

D. Environmental Emissions: The same ACM that is used to monitor gas cabinets, tools and the workplace air may also be used to monitor plant emissions.
More and more the ACMs are being used to monitor the efficiency of wet scrubbers, burn boxes and incinerators to assure that they are removing corrosives, toxics and VOC’s (Volatile Organic Chemicals) from the plant emissions.

The ACM monitors them all.

LARGE SAMPLE POINT AND GAS CAPACITY

The ACM where sold in 4 configurations:

ACMX10: with 10 sampling points capacity
ACMX20: with 20 sampling points capacity
ACMX30: with 30 sampling points capacity
ACMX40: with 40 sampling points capacity

Since the scan rate is about 30 seconds per point, the user must decide how long he can go between sampling any point for the gases monitored by an ACM.
This determines how many ACMs are needed for the facility.
The more points per ACM, the better the economy.

The ACM is capable of monitoring a large number of chemicals in the vapor phase (approximately 100 chemicals on one ACM).
There can be as many as 10 gas groups, known as “analytical methods”, on one ACM.
Typically, an analytical method averages from 3 to 6 chemicals per point. But, any analytical method may have as many as 15 gases monitored at the same time.
It takes no more time to monitor 15 gases than one gas, because FTIR requires no chemical separation.

EXPANDS TO MEET FUTURE NEEDS

The ACM is set up to monitor the gases used today. But, in a few years these gases will change as new tools come into the plant using different gases.
The ACM can be changed to monitor for these new gases by installing updated “analytical methods”. Only the software is changed. The ACM hardware remains the same. So, it is very inexpensive to add and change gases.

The ACM is never obsolete.