The staff starts at zero, on the ground. Every 10 cm is a number, showing ( in meters to one decimal) the height of the bottom of what appears to be a stylised E (even numbers) or 3 (odd numbers), 5 cm high. The stems of the E or 3 and the gaps between then are each 10mm high. These 10mm increments contiunue up to the next 10cm mark.
To read the staff, take the number shown below the reticle. Count the number of whole 10mm increments between the whole number and the reticle. Then estimate the number of mm between the last whole 10mm block and the centre of the reticle. The diagram above shows 4 readings:- 1.950, 2.000, 2.035 and 2.087.
The person holding the staff should endeavour to hold it as straight as possible. The leveller can easily see if it is tilted to the left or right, and should corect the staff-holder. However, it cannot easily be seen that the staff is tilted towards or away from the leveller. In order to combat this possible source of error, the staff should be slowly rocked towards and away from the leveller. When viewing the staff, the reading will thus vary between a high and low point. The correct reading is the lowest value.
Select Back to return to the Introduction screen.