Two Peg Test
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This check must be carried out in the order specified below, and at the intervals specified in the site quality documents. The results must be recorded in the site quality documents.
Preferred Procedure: 1. Record the date and the serial number of the level to be checked. 2. Examine all equipment for obvious damage, bent screws, cracked lenses, loose joints, water penetration etc. 3. If the damage makes the equipment unusable, terminate the test, and arrange for a replacement instrument. 4. Check that the circular bubble remains central when the instrument is rotated180°. If not, correct half the error with the foot screws and half with the bubble adjustment screws. 5. Select two columns, lamp posts or smooth walls, about 30 metres apart and set up the level half way, (+/- half a metre), at position 1. 6. Column 1, position 1, and column 2 must be approximately in a straight line. 7. Mark the cross hair intersection at A and at B. (+/-1mm). 8. Move the level to position 2, about 1 metre from column 2. 9. Column 1, position 2, and column 2 must be approximately in a straight line. 10. Mark the cross hair intersection at C and at D vertically above or below A and B. 11. Measure and record the distances A to D, and B to C. 12. If these two distances are equal, (+/-2mm.). Then the instrument is in adjustment. 13. If this is not the case, repeat the test to check for observation errors. 14. Record all your results and copy to your supervisor.
Alternative Procedure: 1. Record the date and the serial number of the level to be checked. 2. Examine all equipment for obvious damage, bent screws, cracked lenses, loose joints, water penetration etc. 3. If the damage makes the equipment unusable, terminate the test, and arrange for a replacement. 4. Check that the circular bubble remains central when the instrument is rotated180°. If not, correct half the error with the foot screws and half with
This check must be carried out in the order specified below, and at the intervals specified in the site quality documents. The results must be recorded in the site quality documents.
Preferred Procedure: 1. Record the date and the serial number of the level to be checked. 2. Examine all equipment for obvious damage, bent screws, cracked lenses, loose joints, water penetration etc. 3. If the damage makes the equipment unusable, terminate the test, and arrange for a replacement instrument. 4. Check that the circular bubble remains central when the instrument is rotated180°. If not, correct half the error with the foot screws and half with the bubble adjustment screws. 5. Select two columns, lamp posts or smooth walls, about 30 metres apart and set up the level half way, (+/- half a metre), at position 1. 6. Column 1, position 1, and column 2 must be approximately in a straight line. 7. Mark the cross hair intersection at A and at B. (+/-1mm). 8. Move the level to position 2, about 1 metre from column 2. 9. Column 1, position 2, and column 2 must be approximately in a straight line. 10. Mark the cross hair intersection at C and at D vertically above or below A and B. 11. Measure and record the distances A to D, and B to C. 12. If these two distances are equal, (+/-2mm.). Then the instrument is in adjustment. 13. If this is not the case, repeat the test to check for observation errors. 14. Record all your results and copy to your supervisor.
Alternative Procedure: 1. Record the date and the serial number of the level to be checked. 2. Examine all equipment for obvious damage, bent screws, cracked lenses, loose joints, water penetration etc. 3. If the damage makes the equipment unusable, terminate the test, and arrange for a replacement. 4. Check that the circular bubble remains central when the instrument is rotated180°. If not, correct half the error with the foot screws and half with