BOSCH GOL Professional 20 D Optical Level Instruction Manual

: June 13, 2024
: Bosch

Table of Contents

BOSCH GOL Professional 20 D Optical Level
Safety Instructions
Product Description and Specifications
Technical Data
Operation
Setting Up/Aligning the Measuring Tool
Maintenance and Service
References
Read User Manual Online (PDF format)
Download This Manual (PDF format)

BOSCH GOL Professional 20 D Optical Level

Safety Instructions

All instructions must be read and observed in order for the measuring tool to function safely. The safeguards integrated into the measuring tool may be compromised if the measuring tool is not used in accordance with these instructions. Never make warning signs on the measuring tool unrecognizable. SAVE THESE INSTRUCTIONS FOR FUTURE REFERENCE AND INCLUDE THEM WITH THE MEASURING TOOL WHEN TRANSFERRING IT TO A THIRD PARTY.

Have the measuring tool serviced only by a qualified specialist using only original replacement parts. This will ensure that the safety of the measuring tool is maintained.

Product Description and Specifications

Please observe the illustrations at the beginning of this operating manual.

Intended Use
The measuring tool is intended for establishing and checking exactly horizontal height profiles. It is also suitable for measuring heights, distances and angles.

Product Features
The numbering of the product features shown refers to the illustration of the measuring tool on the graphic page.

$BOSCH-GOL-Professional-20-D-Optical-Level- $1$$

Lens
Rough sight
Bubble vial mirror
Eyepiece cover
Adjusting screw for sighting line
Eyepiece
Circular bubble vial
Compensator locking button
Horizontal circle reference mark
Horizontal circle
Adjusting screw for circular bubble vial
Levelling screw
5/8″ tripod mount (on the underside)
Horizontal drive screw
Serial number
Focusing knob
Hex key
Adjusting pin
Case
Plumb-bob

Accessories shown or described are not included with the product as standard. You can find the complete selection of accessories in our accessories range.

Technical Data

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The serial number (15) on the type plate is used to clearly identify your measuring tool.

Operation

Check the levelling and display accuracy of the measuring tool each time before beginning work and after longer transport of the measuring tool.
Protect the measuring tool from moisture and direct sunlight.
Do not expose the measuring tool to any extreme temperatures or variations in temperature. For example, do not leave it in a car for extended periods of time. In case of large variations in temperature, allow the measuring tool to adjust to the ambient temperature before put-ting it into operation. The precision of the measuring tool may be compromised if exposed to extreme temperatures or variations in temperature.
Avoid any impact to or dropping of the measuring tool. Always carry out an accuracy check before continuing work if the measuring tool has been subjected to severe external influences (see “Accuracy Check of the Measur-ng Tool”, page 11).
Place the measuring tool in the provided case when transporting it over longer distances (e.g. in the car). Ensure that the measuring tool is correctly placed in the case. When placing in the case, the compensator is locked, as the measuring tool may otherwise be damaged by strong movements.

Setting Up/Aligning the Measuring Tool

Mounting on the Tripod
Set up the tripod so that it is stable and secured against tip-ping over or slipping. Place the measuring tool onto the thread of the tripod via the tripod mount (13) and secure the measuring tool with the locking screw of the tripod.
Align the tripod roughly.
Over short distances, the measuring tool can be carried whilst mounted on the tripod. In order to avoid damage to the measuring tool, the tripod must be held vertically during transport and should not e.g. be carried lengthwise over the shoulder.

Aligning the Measuring Tool
Align the measuring tool using the levelling screws (12) so that the air bubble is positioned in the centre of the circular bubble vial (7).

Turn the first two levelling screws A and B to move the air bubble so that it is centred between the two levelling screws. Then turn the third levelling screw C until the air bubble is positioned in the centre of the circular bubble vial.
Any remaining deviation of the measuring tool from the hori-zontal plane following the balancing of the circular bubble vial is compensated for by the compensator.
While working, check regularly (e.g. by looking through the bubble vial mirror (3)) whether the air bubble is still in the centre of the circular bubble vial.

Centring the Measuring Tool over a Ground Point
If necessary, centre the measuring tool over a ground point. To do this, hang the plumb-bob (20) on the locking screw of the tripod. Align the measuring tool over the ground point either by moving the measuring tool on the tripod or by ad-justing the tripod.

Focusing the Telescope
Remove the protective cap from the lens (1).

Point the telescope at a bright object or hold a white sheet of paper in front of the lens (1). Turn the eyepiece (6) until the crosshairs ap-pear sharp and deep black. Point the telescope at the levelling rod, using the rough sight (2) if necessary. Turn the focusing knob (16) until the graduation field of the levelling rod can be seen sharply. Align the crosshairs exactly with the centre of the levelling rod by turning the horizontal drive screw (14).
When the telescope is correctly focused, the crosshairs and the image of the levelling rod must not move against each other when the eye is moved behind the eyepiece.

Measuring Functions
Always set up the levelling rod exactly vertically. Point the aligned and focused measuring tool at the levelling rod so that the crosshairs are on the centre of the levelling rod.

Reading Off the Height

Read off the height on the levelling rod at the centre line of the crosshairs.
Height measured in the figure: 1.195 m.

Measuring a Distance

Centre the measuring tool over the point from which the distance is to be measured.
Read off the height on the levelling rod at the top and bottom lines of the crosshairs. Multiply the difference between the two heights by 100 to get the distance from the measuring tool to the levelling rod.
Distance measured in the figure: (1.347 m – 1.042 m) x 100 = 30.5 m.

Measuring Angles
Centre the measuring tool over the point from which the angle is to be measured.

$BOSCH-GOL-Professional-20-D-Optical-Level- $8$$

Point the measuring tool at point A. Rotate the horizontal circle (10) with the zero point toward the reference
mark (9). Then point the measuring tool at point B. Read off the angle at the reference mark (9).

GOL 20 D/GOL 26 D/GOL 32 D: Angle measured in the ex-ample: 45°.
GOL 20 G/GOL 26 G/GOL 32 G: Angle measured in the ex-ample: 45 gon.

Accuracy Check of the Measuring Tool
Check the levelling and display accuracy of the measuring tool each time before beginning work and after longer trans-port of the measuring tool.

Checking the Circular Bubble Vial
Align the measuring tool using the levelling screws (12) so that the air bubble is positioned in the centre of the circular bubble vial (7).
Rotate the telescope by 180°. If the air bubble is no longer in the centre of the circular bubble vial (7), the circular bubble vial must be readjusted.

Readjusting the Circular Bubble Vial

Move the air bubble of the circular bubble vial (7) to a position midway between the end position of the check and the centre by turning the levelling screws (12).

$BOSCH-GOL-Professional-20-D-Optical-Level- $10$$

Using the hex key (17), turn the adjusting screws (11) until the air bubble is positioned in the centre of the circular bubble vial.
Check the circular bubble vial by rotating the telescope by 180°. Repeat the adjustment procedure if necessary or contact Bosch customer service.

Checking the Compensator
After aligning and focusing the measuring tool, measure the height at a reference point. Then press and release the lock-ing button of the compensator (8). Measure the height at the reference point again.
If the two heights do not match exactly, have the measuring tool repaired by Bosch customer service.

Checking the Crosshairs
A measuring distance of approx. 30 m is required for the check. Set up the measuring tool in the centre and levelling rods A and B at both ends of the measuring distance.

After aligning and focusing the measuring tool, read off the heights at both levelling rods. Calculate the difference d between the height a1 on levelling rod A and the height b1 on levelling rod B.

Example:
a1 = 1.937 m
b1 = 1.689 m
a1 – b1 = 1.937 m – 1.689 m = 0.248 m = d

Set up the measuring tool approx. 1 m away from levelling rod A. After aligning and focusing the measuring tool, read off the height a2 at levelling rod A.
Subtract the previously calculated value d from the measured height a2 in order to obtain the set value for the height b2 at levelling rod B.
Measure the height b2 at levelling rod B. If the measured value deviates by more than 6 mm (GOL 20 D/G), 3 mm (GOL 26 D/G) or 2 mm (GOL 32 D/G) from the calculated set value, the crosshairs must be readjusted.

Example:
a2 = 1.724 m
d = 0.248 m
a2 – d = 1.724 m – 0.248 m = 1.476 m
GOL 20 D/G: When measuring, the height b2 must be 1.476 m ± 6 mm.
GOL 26 D/G: When measuring, the height b2 must be 1.476 m ± 3 mm.
GOL 32 D/G: When measuring, the height b2 must be 1.476 m ± 2 mm.
Readjusting the Crosshairs

Set up the measuring tool approx. 1 m away from levelling rod A. After aligning and focusing the measuring tool, read off the height a2 at levelling rod A.
Subtract the previously calculated value d from the measured height a2 in order to obtain the set value for the height b2 at levelling rod B.
Measure the height b2 at levelling rod B. If the measured value deviates by more than 6 mm (GOL 20 D/G), 3 mm (GOL 26 D/G) or 2 mm (GOL 32 D/G) from the calculated set value, the crosshairs must be readjusted.
Example:
a2 = 1.724 m
d = 0.248 m
a2 – d = 1.724 m – 0.248 m = 1.476 m
GOL 20 D/G: When measuring, the height b2 must be 1.476 m ± 6 mm.
GOL 26 D/G: When measuring, the height b2 must be 1.476 m ± 3 mm.
GOL 32 D/G: When measuring, the height b2 must be 1.476 m ± 2 mm.
Readjusting the Crosshairs

Maintenance and Service

Maintenance and Cleaning
Store and transport the measuring tool only in the supplied case.
Keep the measuring tool clean at all times.
Never immerse the measuring tool in water or other liquids. Wipe off any dirt using a damp, soft cloth. Do not use any detergents or solvents.
Handle the lenses with particular care. Remove dust only with a soft brush. Do not touch the lenses with your fingers. Before storing, allow the measuring tool and the case to dry completely. In the case, there is a bag containing desiccant, which binds residual moisture. Replace the desiccant bag regularly.
If the measuring tool needs to be repaired, send it off in the case.

After-Sales Service and Application Service
Our after-sales service responds to your questions concerning maintenance and repair of your product as well as spare parts. You can find explosion drawings and information on spare parts at: www.bosch-pt.com
The Bosch product use advice team will be happy to help you with any questions about our products and their accessories.
In all correspondence and spare parts orders, please always include the 10‑digit article number given on the nameplate of the product.

Great Britain
Robert Bosch Ltd. (B.S.C.)
P.O. Box 98
Broadwater Park
North Orbital Road
Denham Uxbridge
UB 9 5HJ
At www.bosch-pt.co.uk you can order spare parts or arrange the collection of a product in need of servicing or repair. Tel. Service: (0344) 7360109
E-Mail: [email protected]
You can find further service addresses at: www.bosch- pt.com/serviceaddresses

Disposal
Measuring tools, accessories and packaging should be re-cycled in an environmentally friendly manner.

Only for EU countries:
According to the Directive 2012/19/EU on waste electrical and electronic equipment and its transposition into national law, measuring tools that are no longer usable, and, according to the Directive 2006/66/EC, defective or drained batteries must be collected separately and disposed of in an environmentally correct manner.
If disposed incorrectly, waste electrical and electronic equipment may have harmful effects on the environment and human health, due to the potential presence of hazardous substances.

Only for United Kingdom:
According to The Waste Electrical and Electronic Equipment Regulations 2013 (SI 2013/3113) (as amended) and the Waste Batteries and Accumulators Regulations 2009 (SI 2009/890) (as amended), products that are no longer us- able must be collected separately and disposed of in an environmentally friendly manner.