When it comes to RTK systems, there is much to do, even before you have the device in your hands. Choosing the right theodolite for your needs can present its own challenges, but these are easy to overcome when you have helpful advice and friendly support from experts within the field. For just such services, be sure to check out Bench Mark today.
However, the requirements don’t just cease to exist once you have your RTK system in hand. No, they will continue as you learn to use the equipment, care for it and, inevitably, drop or mishandle it. When this happens, don’t panic! Surveying equipment is meant to be durable, so you’ll probably be fine to be a bit rough with it.
Still, surveying equipment must perform one critical function above all others, which is being an accurate measurement tool. When there are questions about this accuracy, it can lead to problems, rework and extra financial burden. So, when you drop, damage or misuse your RTK system, it is important to ensure the calibration of the equipment remains valid and accurate.
Calibration: Two Types
The first type of calibration we will discuss is the service offered by professionals within the surveying industry. This service may be available from vendors, distributors and other equipment handlers. It uses established standards to compare the readings of your surveying equipment with known standards and requires sending the device off to the testing/ verification facility.
The second form of calibration occurs in the field and can be done by you. Occasionally this process is referred to as field verification rather than calibration specifically. In either case, while it can be a great way to ensure the accuracy of your theodolite in the short term, it is always best to receive a proper and complete calibration when you have the time to send your equipment away.
The Process of Field-level Verification
Before verifying the accuracy of your survey equipment, be sure to read and understand all literature provided by the manufacturer of the equipment. While the general process is consistent across most suppliers, finding the right inputs and procedures tends to vary from unit to unit.
Step 1: Roughly Level Your Theodolite
The first step in the process of field calibrating your device is to roughly level it. This means attaching it to the tripod and baseplate and adjusting the bubble level to the centre.
Step 2: Find a Known Value and Adjust
Choose a target at a minimal distance (250-350 feet). This should be your regular target, but any “plus” shaped sign can work. Once you have chosen the target, align the theodolite’s crosshairs with the target’s. Note the vertical angle displayed.
Step 3: Reset the Device and Adjust Again
Spin your device on the baseplate, completing a full rotation. Align the two crosshairs again and note the vertical angle. If it is the same as your first measurement, congratulations! Your theodolite is correctly calibrated.
If the angles do not match, that’s alright. Find the reset button for the measurements and press it. This should zero your measurements, effectively calibrating your theodolite or RTK system device.
Step 4: Repeat for Horizontal Values
Once you’ve completed the vertical verification of your theodolite’s measurements, repeat the process for the horizontal values. This will ensure both angles are properly calibrated and validated.