Bosch GOL 32 D Optical Level: Frequently Asked Questions
The Bosch GOL 32 D is an optical levelling instrument for establishing horizontal levels and comparing heights across a site. This FAQ covers its capabilities, setup, accessories and recommended calibration frequency.
What is the Bosch GOL 32 D used for?
The GOL 32 D is used to establish and check horizontal levels and measure height differences. Typical site tasks include transferring a reference level, checking foundation and slab levels, and comparing ground heights.
It can also measure distances using a levelling staff and horizontal angles using its graduated circle.
Is it a laser level?
No. You look through its telescope and read a graduated levelling staff. It does not project a visible laser line onto the work area.
It is useful when you need to compare levels between points across a site rather than display a reference line on a wall.
What does ā32 Dā mean?
The GOL 32 D has 32Ć telescope magnification and a horizontal angle scale marked in degrees, with a full circle of 360Ā°.
How accurate is the GOL 32 D?
Bosch specifies height accuracy of Ā±1.0 mm at 30 metres for a single measurement.
This does not mean Ā±1.0 mm accuracy across its entire working range. Correct setup, instrument condition, staff positioning and site conditions affect the results.
What is its working range?
Bosch specifies a working range of up to 120 metres. The minimum measuring distance is 0.3 metres.
Choose a position that gives a clear view of the staff. The maximum working range should not be confused with the distance at which the quoted height accuracy is specified.
What accessories do I need?
For normal levelling work, you need a stable tripod with a compatible 5/8-inch mounting thread and a suitable graduated levelling staff.
Check the contents of the selected Solo or Kit package before ordering. Do not assume every package includes a tripod and staff.
Does it level itself automatically?
It has an automatic compensator, but you must first set up the tripod securely and centre the circular bubble using the levelling screws.
The compensator corrects the remaining small deviation from horizontal within its operating range. It does not replace proper initial setup. Check regularly during work that the bubble remains centred.
How do I take a reading?
- Set the tripod on firm ground and secure the instrument.
- Centre the circular bubble using the levelling screws.
- Focus the eyepiece until the crosshairs appear sharp.
- Aim at the levelling staff and focus until its graduations are clear.
- Keep the staff exactly vertical and read its graduation at the centre horizontal crosshair.
When correctly focused, the crosshairs and staff image should not appear to move against each other when you move your eye behind the eyepiece.
Can it tell me the difference in height between two points?
Yes. Take staff readings at both points from the same instrument setup and compare them.
For example, if the readings are 1.500 m at point A and 1.200 m at point B, point B is 0.300 m higher than point A.
A smaller staff reading indicates a higher point when viewed from the same horizontal line of sight. This comparison assumes the instrument has not moved and the staff is held vertically at each point.
Can it measure distance?
Yes, using the upper and lower crosshair lines and a levelling staff.
Subtract the lower reading from the upper reading and multiply the difference by 100. For example:
(1.347 m ā 1.042 m) Ć 100 = 30.5 m
This is a staff-based optical measurement, not a digital laser-distance reading.
Can it measure angles?
Yes. Its horizontal circle has 1Ā° graduations.
Centre the instrument over the reference point, sight the first target and set the circle to zero. Then sight the second target and read the horizontal angle.
The 1Ā° marking is a graduation interval, not a stated angle-accuracy specification.
How often should the GOL 32 D be calibrated?
Bosch Professional recommends recalibrating optical levels once a year.
Recalibration may be needed sooner after a significant impact, suspected damage or unreliable readings. Do not continue relying on the instrument if its accuracy is in doubt.
Annual recalibration does not replace routine accuracy checks before use.
When should I check its accuracy?
Boschās operating manual instructs users to check levelling and display accuracy before starting work and after longer transport. An accuracy check is also necessary after a significant impact or drop.
Follow the manualās procedures for checking the circular bubble vial, compensator and crosshairs. If the instrument fails a check, have it assessed and adjusted as necessary before continuing work.
A routine field check is not the same as formal calibration or a calibration certificate.
Is it suitable for outdoor use?
Yes. It has an IP54 dust-and-splash protection rating. This does not mean it is waterproof or suitable for immersion.
Protect it from moisture, direct sunlight, impacts and extreme temperature changes. Allow it to adjust to the surrounding temperature before use after a substantial temperature change.
How should I store and transport it?
Use the supplied case for storage and longer journeys. Make sure the instrument is correctly seated in the case, which locks the compensator for transport.
Allow both the instrument and case to dry completely before storage. Handle the lenses carefully, remove lens dust with a soft brush, and clean the instrument with a soft, damp cloth. Do not use solvents or detergents.