Tips on Spark Detectionby Bob Bushnell on 05/11/12
We get a lot of questions from people asking if our spark detection system will work for their unique application. There are a wide range of situations where Arcs and or Sparks need to be sensed including, but not limited to:
- Where an arc or a spark is an unwanted part of a process and needs to be detected in order to signal, shut down, or otherwise control the process
- When sparks are expected as part of a process and that process needs to be tested, measured or controlled
- When sparks are required as part of a process and the absence of a spark needs to be detected, reported, or some action needs to be taken.
These situations arise in all kinds of environments and determining if Scanning Devices’ Spark Detection solutions work can sometimes be more of an art than a science. Still, there are some general principles for spark detection that should be considered when evaluating our products as a potential solution. Here are just a few:
- Our spark detection systems work best when attempting to sense sparks or arcs in the near infrared region where electrically generated arcs radiate. Flames or sparks generated by combustion radiate in the ultraviolet region and are not often good sensor targets.
- How much ambient light is in the area that you wish to inspect for a spark? Because our sensors are looking for changes in light, the presence of ambient light can interfere with the detection process. Our products work best if the areas you are viewing for sparks are protected from ambient light. Enclosed areas like microwave oven wave guides, test chambers, motor enclosures, or other protected areas improve the likelihood that arcs and sparks can be detected.
- How close to the expected source of the spark can you position a sensor? In a wave guide for a microwave oven, being close to the potential source is less important because you are sensing larger enclosed areas with little ambient light and reflective surfaces. In these applications you can view larger areas with success. If you are inspecting for a spark as part of a process where the spark is small in size (like the spark at the contact point of an electronic ignition system) then being close to the known location of the expected spark can be extremely helpful to successful spark detection.
- Cleaner environments work better. Each sensor has a glass or plastic lens that looks into the areas being monitored. If large amounts of dust or material are present it can make it challenging to detect a spark, and or, can demand routine cleaning of sensor lenses to assure accurate spark detection.
- How wide an area do you want to inspect? Our sensors provide a 60 degree viewing area from the head of the sensor out into the location you are inspecting. In some applications it is important to use multiple sensors to assure you have covered the full viewing area you want to inspect. This is more likely if you don’t know exactly where to expect the spark or arc and the inspection area is large.
- Food or non-food environments - Scanning Devices offers sensors with both Plastic and Glass lenses, typically, sensors used around food are required to be plastic not glass. In addition, sensors with glass lenses can withstand higher temperatures. Glass Sensors operate in ranges -65 degrees C to 125 degrees C, Plastic lenses are appropriate for temperatures from -20 degrees C to +70 Degrees C.