Planeness testing apparatus

An apparatus for testing planeness of a workpiece, comprising:

• a platform configured for supporting the workpiece thereon;
• a bracket vertically mounted to the platform;
• a testing system mounted to the bracket, comprising:
• a test dial indicator having a sliding pole;
• a supporting tray mounted to the bracket and comprising:
• a first sidewall parallel to a moving direction of the sliding pole;
• a second sidewall adjacent the first sidewall and facing the test dial indicator;
• a concave defined in a junction of the first sidewall and the second sidewall;
• and
• a through hole defined in a middle portion of a sidewall of the supporting tray opposing to the second sidewall, and communicates with the concave;
• a testing member, with one end thereof being connected to the sliding pole, and comprising a vertical section and a horizontal section perpendicularly extending from the vertical section, wherein the vertical section is configured for contacting the workpiece, and the horizontal section slidably passes through the through hole of the supporting tray and is received in the concave;
• and
• a fine-tuning member for controlling the movement of the testing member;
• wherein when testing, the fine-tuning member drives the testing member to move toward the workpiece until the testing member contacts the workpiece, the sliding pole extends together with the testing member, a value shown by the test dial indicator shows a moving distance of the testing member.