We mean that we’ve taken the best tools of modern factory automation, and have made them available to you, for the first time, in an automation based gas detection system.

But before we give you more details on what’s new, let’s reminisce…



If you’ve ever tried to put together a gas detection system, you know that it could be a real challenge.

Generally, a particular manufacturer’s sensor would be compatible solely with its own controller. All but the most rudimentary output functions (anything beyond simple alarms) would have to be worked out and added, by you, separate from the system, as originally supplied.

Suppose, for example, that you wanted to control fans in a parking garage using CO concentration and time of day, and preferred that the CO control be based on evaluating conditions at several sample points simultaneously.

TOUGH LUCK. Most gas detection systems provide alarm contacts, only. The rest was up to you.

If you wanted data acquisition, you called in another vendor. More likely than not, you were forced to download to produce your reports, which had to be configured in still another software package.



Because in the rarefied world of instrumentation, “data acquisition” invariably implied laboratory (short term studies) rather than process (long term monitoring) applications. If you were very persistent, and very expert, you could probably conjure up something resembling a process data acquisition and trending capability. For many, though, it was not worth the effort.

Thus, despite the obvious regulatory and tort liability implications, few gas detection systems extant are equipped with appropriate data acquisition.

Finally, the operator interface, if one could even call it that, would usually be sorely lacking. Panel controls were anything but intuitive, and were often clumsy. But, you accepted it—because that’s the way it was done.

Suffice to say, it took such an extreme effort to get the functionality you needed, you probably just settled for a third rate version of your original concept.

In short, you didn’t get a warm and fuzzy feeling from your gas detection system.


Interscan has changed all that for good!


Using these basic elements——

  • A Programmable Logic Controller (PLC)

    A PLC is essentially a central processing unit containing a program, which is connected to input and output devices. The program controls the PLC so that when an input signal from an input device turns on, the appropriate response is made. The response normally involves turning on an output signal to some sort of output device. The input devices could be sensors, switches or keypads, or any other device that can produce a signal compatible with the PLC. Typical PLC outputs are discrete voltage, analog signals, and relay contacts, to name only a few.

    Further control capability is realized via internal counters, timers, math processors, and various specialized add-on modules.

  • Sensors
  • Operator Interface or PC

      ——the closest thing yet to a perfect system is achievable.

ANY sensor with an analog, digital, or discrete output connects to the PLC.

In the PLC, control logic, fulfilling your exact specifications, runs the system. .Here, alarm comparisons are made, calibrations are performed, all control outputs are initiated and an almost limitless variety of special features can be accomplished.

As such, any control scheme, no matter how elaborate, can be attained with ease—completely within the Interscan system. If you can describe it, we can do it!

If data acquisition or trending are not required, the “front end” or operator interface is usually some type of programmable touchscreen device. The screen displays are individually configured, to suit your application.

In smaller systems, a workstation, featuring a four line alphanumeric display with a programmable keypad, can be employed.

Should data acquisition or trending be necessary, your operator interface and data center are a PC, functioning as a true SCADA (Supervisory Control and Data Acquisition) system. Interscan also offers Arc-Max®,a feature-rich stand-alone data acquisition/archiving/reporting package, adaptable to any monitoring system.

With SCADA, a phenomenal range of reporting and graphics options are available. .As in all of our systems, the design is set up with your specific requirements in mind—and can be modified anytime you wish.

Some popular options are:

  • Live trending
  • Historical trending
  • Customized report generation
  • Plant or process diagram on-screen, with current sensor values and alarm conditions displayed at their respective locations
  • Password protection



It means that the features in any system are limited only by your imagination. And it means that should your needs change, system operation can be re-programmed at nominal cost.

You can mix and match toxic, combustible and process sensors—yours, ours, theirs—without worrying about anybody’s proprietary controller. Should your plant be standardized on a certain brand of PLC, no problem. Interscan can build systems around any commercially available PLC.

Each system comes with complete documentation, so you’ll never be “locked in” again. And nothing, but nothing, is as reliable or flexible as a PLC.

Should you choose the SCADA route, Interscan will create an application—using any number of popular SCADA software packages, specified by you or by us—putting you in the company of tens of thousands of satisfied users running everything from small machines to huge process plants.

The end result….

That warm and fuzzy feeling at last!



  1. List the gas or gases of interest and also any interfering compounds that may be present. Note the approximate concentrations of each, and desired full scale measuring range(s).
  2. List any other process sensors you wish to incorporate into the system, along with their ranges of measurement.
  3. Indicate the monitoring locations, relative to each other and to the main control panel. A rough sketch is quite helpful.
  4. Describe desired alarm operation.
    • Consider how many levels of alarms are required (Low, High, and additional levels)
    • Specify any delays (both on actuation and release)
    • Explain any grouping of alarms (whereby alarm levels from multiple sampling locations are evaluated in concert to activate an additional function)
  5. Discuss any further inputs and outputs, such as panel mounted alarm test or defeat switches, remote overrides, door interlocks, and phone dialers.
  6. Detail your data acquisition and trending needs, and the preferred report formats.

If any of this sounds unfamiliar, don’t worry. We will guide you through it, making sure that your system design provides the best functionality and safety at the best possible price. Your total satisfaction is our goal.



Contact one of our applications experts and tune in to the state-of-the art in gas detection.