Automatic level operator's manual
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Controls
Roll your mouse over the parts of the level to find out their function.
Set up
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Click on the arrows to move forwards or backwards. Choose your set up site carefully. It should be:
As you will be spending a fair amount of time using the level, make sure that the tripod is set up at a comfortable height for you to look through. You should not be crouching or on tip toes to look through the sight of the level. The tripod height can be adjusted by extending or retracting the tripod legs. Once the tripod height has been adjusted, push the legs into the ground to secure the tripod position. Position the automatic level on the top of the tripod but do not lock it in. The level has a bubble on it, similar to a spirit level. Manoeuvre the level until the bubble is in the exact centre of the circle. Aligning the bubble correctly will be made easier if the tripod has a domed top on it. Once the bubble is centred, carefully lock the level onto the top of the tripod by screwing the locating bolt into the base of the level. Unless you have an extremely steady hand you will find that after you have secured the level the bubble will be off centre. Use the adjustable legs on the base of the automatic level to move the bubble back into the centre of the circle. Now adjust the focus of the viewfinder so that a clear image of the cross hairs is established. A datum or reference point must now be established. As all your future measurements will relate back to this point it is vital that you measure this accurately. This point should be:
If a fixed object is not available, you will need to drive a surveyor's peg into the ground to ground level. To protect your datum point, surround it with at least three protective pegs and brightly coloured surveyor's tape. Make sure that all machinery operators and staff working on the site are aware of the location of the datum point and its importance to the project. Finally, take a measurement at the datum point using the surveyor's staff and automatic level. Write this measurement down and store it in a safe place. Do not rely on your memory! |
Centring the bubble
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It is essential that the spirit level bubble on the automatic level is centred, otherwise all your measurements will be incorrect. |
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This is done by using the three adjustable legs on the base of the level to manipulate the position of the bubble. This can be a tricky process, so the more you practise it the better your skills will become. |
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The spirit level bubble is centred correctly.
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The spirit level bubble is off-centre.
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Focussing the site
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Use the focussing knob to bring the image in the viewfinder into clear focus. |
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Then adjust the eyepiece so the cross hairs in the viewfinder are in focus. |
See if you can focus the level correctly so that you can clearly see the staff and the cross hairs through the viewfinder.
Click on the white arrow heads to focus in or out.
What is the reading on the staff? If you are not sure, brush up on your staff reading skills.
The surveying staff
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A level is of little value without a staff. Most staffs are made of aluminium and are of three stage telescopic construction, extending out to between 3 and 4 m in height. When using a staff, make sure it is: |
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Warning! Aluminium staffs should never be used in close proximity to power lines. There is a severe risk of electrocution if an aluminium staff comes within 1.5 m of a power line. |
Reading a staff accurately
The reading face of a staff is graduated in 10 cm units with 1 cm divisions. The first 5 cm of a 10 cm unit take the shape of an 'E' whilst the second 5 cm are depicted by two squares.
Drag your cursor up the graduations on the staff to view the measurements.
Holding the staff correctly
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The person holding the staff should stand directly behind it and make sure that their fingers do not obscure the graduations on the face. The staff must be held exactly vertical to achieve an accurate reading. Some staves have levelling bubbles on them to help achieve this. If a levelling bubble is not fitted, the staff should be slowly tilted back and forward along the line of sight. When the staff is not vertical, a higher reading will be seen. Therefore, the lowest reading will be the most vertical. |
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Use the Tilt back and Tilt forward buttons below to see how readings are affected when the staff is not vertical.
Using the level
Once the level has been set up and a datum point established, recording of measurements can commence.
Understanding of level readings can be made easier by keeping the following in mind:
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The higher the reading the lower the ground level The lower the reading the higher the ground level. |
Measure the following points on the landscape below. You have measured the datum point as 1.5 metres. Click on each staff to take a reading through the viewfinder, then select the correct reading from the radio button choices provided.
See if you can answer the following questions. Click on a button to register your answer.
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