Very simply, since no two toxic gas detection applications are the same. We admit that this concept has been obscured under the quite false rubric that “All gas detection is confined entry.”
Certainly, a goodly percentage of all portable gas detection instruments are designed as if they are intended for the confined entry application. These virtually indistinguishable products—from sundry manufacturers—offer detection capability for:
- Oxygen
- Combustibles
- One or more toxic gases
When one of these instruments is purchased, any applications engineering (if you can call it that) is limited to selecting which toxic gases the user wants to measure. Throw into the mix the assortment of tiny, disposable personal gas detectors, in which even less applications knowledge is required, and you have a situation whereby the “standard of care,” so to speak, for much gas detection applications engineering is not exactly high.
This situation might not be so bad if all gas detection requirements were as simplistic as this model would suggest. However, this is not the case in the real world.
For one thing, interfering gases are often a factor. For another, the performance requirements for a fixed, permanently installed gas detection system are far more rigorous than those for a portable unit, used only intermittently.
Continuous operation demands more robust components and design. The system must survive the rigors of the environment—including weather conditions, rough-and-tumble plant operations, and hazardous area classification. While some of these factors might apply to confined entry units, the sheer scale of the problems is at least an order of magnitude greater.
Many applications do not have a clean and dry sample, even if it is supposedly ambient air. What type of filtration and sample cleanup should be used? Other applications require the monitoring of process streams, where more elaborate sample conditioning is needed. None of this can be shoe-horned into the confined entry model, but we have actually replaced systems whereby an unprotected diffusion head sensor was placed directly into a wet and particulate-laden process stream. Not surprisingly, that simple-minded approach did not work!
Sometimes, if the detection portion of the application is straightforward, the user may have unusual packaging, control, or data acquisition requirements. Experience has shown that maximum customer satisfaction results from the gas detection vendor addressing all aspects of the application, rather than the customer conforming his needs to what the vendor has to offer.
Once in a while, potential customers get impatient with the probing questions from our salespeople. “Do you want the order or not?” they might ask. Of course we want the order. But we also want to keep you as a satisfied customer. This used to be called “Winning customers, not just orders.” As such, we’ve got to know what you really need.
The only way to address customer needs is to discuss the application. That’s why you need applications engineering.