Digital Level vs Automatic Level: Which Do You Need?
An automatic level (also called an auto level or optical level) is a telescope that levels itself: you sight the staff and read the height by eye. A digital level reads a barcode staff electronically, so it calculates and stores the height and distance for you. Both rest on the same principle, a compensator that keeps the line of sight level. The difference is who does the reading and the math. If you set grades and check elevations on site, an automatic level is fast, rugged and inexpensive. If you run long level loops, monitor settlement or need records you can hand to an engineer, a digital level pays for itself in time and avoided reading errors.
Digital level vs automatic level at a glance
| Automatic level | Digital level | |
|---|---|---|
| How you read it | By eye, on a graduated staff | Electronically, on a barcode staff (by eye as a backup) |
| Accuracy (1 km double run, ISO 17123-2) | 2.5 mm (Leica NA320 / NA520 / NA720) down to 1.6 mm (NA532) | 0.3 mm (Leica LS10) or 0.2 mm (LS15) to an invar staff |
| Recording | Field book or a separate data collector | Stores heights, distances and full level lines on board |
| Calculations | Done by hand | Done by the instrument: rises, falls, loop closure |
| Power | None needed | Battery (about 10 to 12 hours on an LS10/LS15) |
| Best for | Site grades, forms, footings, quick elevation checks | Benchmarks, long level runs, settlement and deformation monitoring |
Automatic levels: simple and reliable
Set the level up, rough-level the circular bubble, and the compensator does the fine leveling. Sight the staff, focus, and read the height at the crosshair. There's nothing to charge and very little to go wrong, which is why an auto level is still standard on most job sites.
The main differences between models are magnification and accuracy. Leica's NA300 and NA500 lines come in 20x, 24x and 32x versions, and the NA700 line in 20x and 24x. Higher magnification lets you read the staff clearly at longer distances, and accuracy improves with it: the NA320 is rated 2.5 mm per km double run, the NA324 2.0 mm and the NA332 1.8 mm; the NA500 versions tighten that to 1.9 mm (NA524) and 1.6 mm (NA532).
- NA300 series (NA320, NA324, NA332): the everyday construction level for grades, forms and footings.
- NA500 series (NA520, NA524, NA532): a step up in accuracy at the 24x and 32x levels (1.9 mm and 1.6 mm).
- NA700 series (NA720, NA724): 2.5 mm and 2.0 mm, with a wider field of view than the NA300 and NA500 at the same magnification.
Every automatic level depends on the person reading it. Misreading a staff, writing down the wrong number or adding a column wrong are the most common sources of error, and they get worse over a long day or a long level run.
Digital levels: accuracy and records without the reading errors
A digital level aims at a barcode staff and reads it electronically, typically in about 2.5 seconds. It measures the height and the distance to the staff at the same time, applies the collimation correction automatically and stores the result. Run a level line and the instrument keeps track of backsights and foresights, rises and falls, and loop closure, so the numbers you take back to the office are the numbers you measured.
The Leica LS10 and LS15 are rated 0.3 mm and 0.2 mm per km double run to an invar staff, and about 1.0 mm to a standard staff. Electronic readings work from 1.8 m out to about 110 m depending on the staff. They store around 30,000 measurements internally, export to a USB stick and connect by Bluetooth. If the barcode can't be read, you can still read the staff optically.
The LS15 adds autofocus, an overview camera for aiming and documenting setups, a compass, an electronic bubble with tilt check, and the 0.2 mm accuracy option. The LS10 covers the same core measurements with manual focus.
Digital levels make the most sense when:
- You set or check benchmarks and need to show your closure.
- You run long level lines, where reading and booking errors add up.
- You monitor settlement or deformation over time and need the same procedure every time.
- Your client or engineer wants digital files, not a scanned field book.
Which one should you buy?
- Choose an automatic level if your work is site grades, form checks and elevation transfers over short distances, and the crew already reads a staff confidently. An NA324 or NA524 package covers most construction work.
- Choose a digital level if you do survey-grade leveling, benchmark networks or monitoring, or you want every reading stored and reduced automatically. The LS10 is the starting point; the LS15 adds autofocus, the camera and the 0.2 mm option.
- Consider a rotating laser if you mostly set grade across a site with one person. That's a different tool, covered in types of laser levels.
Whichever you choose, check it regularly. A level that's out of adjustment reads wrong at every setup. Both types can be checked in the field with a two-peg test, and the LS10/LS15 have a built-in check and adjust routine. We also handle repair and calibration as a Leica Geosystems Authorized Service and Distribution Partner.
Get help choosing
Tell us what you're leveling, over what distances and to what tolerance, and we'll point you to the right instrument and staff. Talk to our team or browse lasers and levels.