The dial positions that are easy to operate reduce the burden on the wrists and shoulders of the users and thereby improve the operability. The aluminum surface has a high durability compared to paint, to maintain the quality in the long-term use. By placing information illuminations on the dials, the visibility is improved and the risk of an accident due to maloperation during tests is reduced. By means of displaying the set values on a graph, the maximum and minimum values for the test target that vary every time in various tests are shown visually and intelligibly to make it easy to recognize the situations of manual operations.