Dumpy Level

A dumpy level, builder’s auto level, leveling instrument, or automatic level is an optical instrument used in surveying and building to transfer, measure, or set horizontal levels.

The level instrument is set up on a tripod and, depending on the type, either roughly or accurately set to a leveled condition using footscrews (levelling screws). The operator looks through the eyepiece of the telescope while an assistant holds a tape measure or graduated staff vertical at the point under measurement. The instrument and staff are used to gather and/or transfer elevations (levels) during site surveys or building construction. Measurement generally starts from a benchmark with known height determined by a previous survey, or an arbitrary point with an assumed height.

A dumpy level is an older-style instrument that requires skilled use to set accurately. The instrument requires to be set level (see spirit level) in each quadrant, to ensure it is accurate through a full 360° traverse. Some dumpy levels will have a bubble level ensuring an accurate level.

A variation on the dumpy and one that was often used by surveyors, where greater accuracy and error checking was required, is a tilting level. This instrument allows the telescope to be effectively flipped through 180°, without rotating the head. The telescope is hinged to one side of the instrument’s axis; flipping it involves lifting to the other side of the central axis (thereby inverting the telescope). This action effectively cancels out any errors introduced by poor setup procedure or errors in the instrument’s adjustment. As an example, the identical effect can be had with a standard builder’s level by rotating it through 180° and comparing the difference between spirit level bubble positions.

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Hire Guidelines and Thing you should Know.

•If we deliver you must phone for collection. • Machines are not insured, if not returned you pay for the replacement. • Make sure you know how to use the tools. Ask if you need help. Also, make sure of safety requirements. • Hires are charged for time out – not time used. Minimum 1 day (1 day = 24 hrs) • Scaffold is charged weekly, all other tools daily. • Tools must be returned Clean. e.g., if you paint onto a ladder, we charge for cleaning. • Negligent damages get charged separately. • Consumables not used may be returned for refund. • Only use heavy-duty extension leads, not thin household leads. • If you pay by cash we can refund in cash, if you pay by card we refund onto the card. (no debit cards) Card refunds can take up to 10 days. • Weekend hire starts after 2 pm Friday until 9 am Monday = 1-day charge. If you are late on Monday it is for 2 days. • If you keep machines for a long time we can give you a better rate.