First off, where did the term dumpy originate?
A dumpy level is a shortened version of an old optical level that was used on building sites etc for horizontal levelling. The innovation was to engineer the construction of the instrument so that it was shorter or “dumpy” which made it easier to transport and setup.
Automatic levels
have an internal compensator and use a circle bubble for fast setup. That means when the bubble is in the circle the compensator will automatically adjust to horizontal. You do however want to turn the instrument 180 degrees and check that the bubble is still in the circle and then another 180 degrees to make sure. It is easily adjusted with the “footscrews” but this is usually unnecessary.
Dumpy Level
Dumpy levels
have no compensator and use bubble vials. There is no compensator so you have to manually adjust with the footscrews, turn the instrument 180 degress, check, adjust, turn 180 degrees again, adjust and so on until the bubble is central in the vial turned in both directions. Sounds time consuming yes? It is! So why use one? These type of optical levels are more accurate and is generally the choice of surveyors and engineers.
Also if you’re working in a high vibration area an “Auto level” will be difficult to read. This is because the internal compensator will bounce and vibrate which is obvious when you look through the eyepiece.
But the slang “Dumpy” has stuck and is applied to both types as they essentially look the same.
There are many variables when considering a new unit. As previously explained, an auto level has an internal compensator and is a cheaper otption as its accuracy is not as good as a dumpy. Many cheaper manufacturers make this type of level so to get a good one you need to talk with a specialist or someone that has one. There are heaps of builders out there and most will have an optical level of some type, so you can ask a tradesman.
The dumpy level is more expensive and because of the accuracy demand of this instrument, only quality brands will manufacture this type so be prepared to pay for it.
Second hand is an option but if the unit has been dropped (and not obvious) it may be unrepairable. They are a delicate instrument, even though the way some people throw them around you wouldn’t think so!
Finally if you’re not sure you can always hire one. There are plenty of hire units around, just do a search with your location in the search phrase.
I hope this has been of some assistance.
I have done my level best!
