The movie to the left will instruct you how to perform the two peg test for the automatic level.

• The file uses FlashMX which requires the Flash player 6. If your computer does not have this plug-in you will be prompted to download it.
• The file is about 5.6mB, so you will need reasonable bandwidth.
• This movie has sound content.
• Press the play button. Its the symbol !

Nothing is perfect

No optical instrument can be manufactured perfectly and without error- and during the life of an instrument, calibration may be affected by knocks and other factors like temperature change. Observation of instrument error and re-calibration is periodically required for survey instruments. For the level the procedure is the two peg test.