The user title would definitely vary from location to location. Where I worked at a salt mine the tests were performed by our lab technician. Typically they perform what is a called a sieve analysis to determine the particle size distribution of their product. The size and type of sieve used is determined by the typical particle size of the product to be analysed. Sieves are stacked together and a pre-weighed representative product sample is placed on the top sieve. This stack is then placed in a sieve shaker for a specific length of time. Each sieve is then separated and the product remaining on each sieve is removed and weighed individually. The end result is a percentage retained on each sieve.

One of your best sources of information would be to visit http://www.wstyler.com/html/testsieves.html and gather as much information from them as possible.

Also there is no problem asking a company "Can you connect me to the person who does your Sieve Analysis?". The person answering the phone only wants to know how to direct your call. I used to get calls forwarded to me all the time from people asking "Can I speak to someone in Engineering?"

Good luck. ■