This test is required on all Peri-Pro or manual processors and is required if the office does not have a pan or ceph cassette available for quality control testing. The front of the device looks like this:

The directions on this testing device are very good. The basic process involves inserting an un-exposed intra-oral film beneath the copper square. You bring an intra-oral X-ray head down on the device so that the cone covers the copper square. You then expose the film using normal settings and time for a posterior bitewing. After processing the film, it has a density on it. Take the Crabtree device and flip it over. The back looks like this:

The exposed film gets inserted on the top and a slider with different comparative densities that are numbered gets moved back and forth until they match the exposed film?s density. You record the number. If processing is working and your technique is normal the device should match the test film on a 3, 4, or 5. This test is a simple fast, cost effective way to check your processor for proper operation.

The Crabtree Device is available directly from Xray QC @ 970-470-0859 or you can visit their website at http://www.xrayqc.com/