The laser distance meter and other measurement tools
Since I often have to do field measurements, I have started using a Hilti laser distance meter. In the past I used long and short measuring tapes and often a helper when measuring large structures. I have found that using a laser measurer eliminates the need for a helper. The laser distance meter is also much safer in that you can stay on the ground and shoot the laser beam up to to the high object you want to measure, rather than climbing up and hanging measuring tapes from high places.
In the past I had to have a customers maintenance crew operate a cherry picker or high lift table to get me up to the item that needs to be measured. The laser distance measure often eliminates the need for that.
Laser distance measurement cant accomplish everything I need but it does help a lot. Circular objects like large diameter hvac ducts are still difficult to measure when they are high up but at least I can get on either side of the duct and shoot the laser from a known reference point and subtract the laser measurement device distances form the known distance to get my duct diameter. I also use this technique to measure things like storage tanks and round bins although the good old measurement tape often works best in these situations.
The laser distance meter I use is the Hilti PD-30. There are fancier models available but I have talked to a few people who own those models and they tell me they hardly ever use the extra fancy features. In the dusty and dirty places I often measure in, I can see how it would be difficult to use extra buttons and detailed calculations. I am happy that my meter records the last 3 measurements I measured so I can get down from where I am measuring and write the figures down, checking against known distances where I can.
Leica is a german company who have some pretty sophisticated measuring tools that can be used by engineers, contractors and renovation professionals which are not overly expensive considering the features they provide. The laser measurer below stores point to point measurements for walls, ceiling and just about anything else you care to measure.