This is the second part of the GUIDE we have released on the most crucial items to consider when purchasing an oven or sterilizer. In this paper, we will discuss PROCESS CONTROL and how this can affect your product.
All manufacturers will state that their equipment employs an electronic controller, but actually, what does this mean? Not much! Be careful.
For example: would you purchase an old-style, mercury-based air conditioner thermostat for your home? No way! These controls lack precision, your temperature will reach inconsistent highs and lows, and this will undoubtedly annoy you.
Ovens and sterilizers are the same, but in a far more critical state. You could destroy your production, your reputation, your career with an incorrect choice of oven or sterilizer.
First, you have to know how much temperature (or any other critical parameter, humidity is a good example) variation your process will accept without being affected. Not all equipment manufacturers will be able to meet your standards, and this is important to have in consideration. Imagine the result of purchasing a piece of equipment and realizing, after installation, that the precision this equipment offers is not acceptable for your process? No easy (and inexpensive) fix for that.
The control is the brain behind your equipment. It’s the control that will tell all parts in the equipment you purchased what and when to take an action. What would happen to your process if the control that equips your oven or sterilizer is too slow to react to an input? And what about if the reaction has no precision?
One of the most advanced technologies in the field for process control is called “FUZZY LOGIC” and the best and easiest way to explain this concept is by making an analogy with the way a car is operated.
Imagine an on/off switch instead of the standard gas pedal. If you had to move, you would push the “on” button, and the engine will deliver 100% of all available energy (horsepower). You will get to the desired speed very fast, and in most cases, the car will be challenging to maneuver (not to mention the excessive engine noise and tire overrotating and fogging). As soon you hit close to your target speed, you will turn the gas switch to off. The speed would remain increasing for a bit and will cross your desired speed because of the inertia (and this is what we call overshooting), and then it will start to drop. Depending on the low-speed point, you would activate the gas switch to “on”, and all energy will be delivered once again. This process will repeat itself until you get to your destination. It’s safe to assume that the ride would be unpleasant. As another result, the car would have increased wear and tear; you would be consuming a lot of gas and putting yourself at a high risk of getting a speeding ticket. If we were to plot the speed graph for this example, we would have the following image:
Newer controls have upgraded this on/off switch to what you see in your car: a proportional gas pedal, but alone, that’s not the answer for an efficient process. Even with this upgraded system, you would still depend on the driver skills to choose a reasonable acceleration rate and rely on all his attention to maintain the desired speed. How does this sound? It’s better, no question, but is it enough for your process? You will still be at risk of a speeding ticket and some unwantaed extra gasoline consumption.
In another upgrade, the industry offers PID + FUZZY LOGIC control. That’s your brand new top-notch car with adaptive cruise control. The system will evaluate all necessary parameters and conditions to determine how to increase and maintain the speed. Virtually no over-speeding or under-speeding because the system will learn from the ride itself and will adapt the responses to the gas pedal push/release. Your car is at the optimal wear and tear, you will be running at an optimal mileage rate, and no risk of a speeding ticket. Isn’t that phenomenal? Of course, it is. Here is how the graph looks:
This is exactly what happens with your oven or sterilizer.
We hope we were able to give you more information in terms of how to evaluate which equipment to purchase. If you should like to discuss, comment, or ask us anything, please feel free to contact us at firstname.lastname@example.org.