Are you looking at buying a professional quality automatic (dumpy) level, but not wanting to spend a fortune? Well, one such automatic dumpy level that you should consider is the latest Topcon AT-B4A. This is one of the dumpy levels that didn’t make it on to my list of the best dumpy levels for under £200 as the Topcon AT-B4A is currently available for around £240 including VAT
Where does the Topcon AT-B4A sit in the Topcon Automatic (Dumpy) Level Range?
There are 3 models in the Topcon AT-B range, the Topcon AT-B4A, the Topcon AT-B3A and the Topcon AT-B2. The Topcon AT-B4A is the entry level Auto Level in the AT-B Series from Topcon and supersedes the Topcon AT-B4 model that was based on the Sokkia series of Auto Levels.
Topcon describe the AT-B series of Auto levels as durable, dependable, high value auto levels. They all share the same type of compensator, the same ultra-short focusing and the same protection from the harshest of weather. But what you want to know is, Is It Any Good?
In a nutshell, Yes. Why do I say this?
I have had a Topcon AT-B3 for several years now, using it on many construction sites throughout the country. It has always been accurate, with clear optics and has never gone wrong. That’s why I find it to be one of the best automatic dumpy levels available on the market. Read more about the Topcon AT-B3 on this website here.
Topcon AT-B4A is the entry auto level in the Topcon AT-B Series of Levels.
Setting up the Topcon AT-B4A is straightforward and easy. Just setup your survey tripod (either the aluminium or wooden type) relatively level, on sturdy ground. Then securely fasten the Topcon AT-B4A to your tripod and use the three adjusting screws and the circular levelling vial to bring it into the compensator’s operating window.
What type of Compensator does the Topcon AT-B4A have?
The Topcon AT-B4A has a pendulum compensator and consists of four suspension wires made from a super high tensile metal and a magnetic damping system. This construction provides durability and accuracy of the compensator system over a wide range of temperatures. The compensator works over a range of 5 degrees from the horizontal plane, ensuring that even the slightest inaccuracy in the levelling vial is accounted for. Another advantage of this system is that vibrations from nearby heavy construction plant are quickly overcome allowing readings to be taken once more.
What is the shortest distance that can be seen through a Level?
The Topcon AT-B4A has a very short focusing ability. Reading a staff from just 200mm away is far better than any other auto level from other manufacturers. This is a handy advantage when working close up or wanting to be close to a datum point.
What is the Magnification of the Topcon AT-B4A?
The Topcon AT-B4A has a magnification of 24times, significantly more than other manufacturers’ base auto levels, and the field of view is a wide 1 degree and 25 minutes. The image is erect (staff is viewed upright) and there are also the stadia marks on the cross hairs to allow for distance readings to be taken from the staff.
What is the Stadia Mark Ratio on the Topcon AT-B4A?
These stadia marks are set at the standard 1:100 ratio. The focusing on the Topcon AT-B4A is a single speed adjustment. It also has a horizontal circle for angle measurements to the nearest degree, it is free to rotate so that angles can be easily read from a zero datum.
Can Topcon AT-B4A be Used in the Rain?
Like any automatic (dumpy) level, the Topcon AT-B4A can be used in wet conditions. Just remember to dry it completely before storing it away in the closed carry case. The Topcon AT-B4A has a rating of IPX6 which means that it there is no data available on dust protection, but it is protected from powerful water jets (a test that lasts for 3minutes using 100 litres every minute). This protection helps prevent condensation forming inside the telescope.
For more information on the IP rating system look on the enclosure company website.
What is the Accuracy of the Topcon AT-B4A?
The accuracy for a 1km double run levelling run is quoted by Topcon as being 2.0mm for the Topcon AT-B4A. There is no micro-meter available to increase the accuracy quoted for the Topcon AT-B4A. A 2.0mm accuracy for taking levels over a distance of 1000m is very good.
What is the cost of the Topcon AT-B4A Automatic Level?
Expect to pay around £200+VAT for the Topcon AT-B4A without 5m E-Grad staff and Aluminium tripod. Expect to pay around £50 including VAT for an aluminium E-Grad Staff, check the latest prices on Amazon. And around £60 for an aluminium survey tripod, check the latest prices on Amazon.
Remember that you should always contact your preferred survey equipment supplier for more information or to purchase.