I volunteered for racket control once in one of the ittf junior circuits. We had a list of all the approved racket coverings to make sure they were using a legal rubber, and then we had to check if the rubber extended over the limits of the blade. The man doing racket control usually did this. There are other things he needed to check too. Next we used a Mini-RAE Lite machine to test for VOC's. The machine costs over US$2000. It has a metal cup which you place over each rubber for 20 seconds. The problem was the room we were in was very humid, and there were so many rackets coming in and out. We would always have to start the test when the reading was over 2.0 ppm (We would take difference from the start reading to the end reading) and whenever it went over 3.0 ppm the machine would start beeping. They told us to close the door because the beeping was distracting the players, which made the room even more hot, and the beeping was bouncing off the walls and driving us crazy! Then we had a device to test the rubber thickness (under 4.0 mm) and the rubbers could not be too concave or convex. The worst part was that players kept showing up right before their match starts when they were supposed to show up 20 minutes before, and we have to check 20 rackets in 5 minutes! And for every racket we had to write a report of what rubber they were using, the ppm reading, the thickness of the rubber, etc...we had to use paper bags to deliver the rackets to the umpires.
