# Total Station Accuracy Calculator

Free online calculator to see how accurate a total station is over a specified distance.

Article By: Tom Ayre | Last Update: August 2021

Knowing how accurate your total station can operate to is important. On projects where tolerances are particularly tight (setting out / topographical surveys) it is useful knowing what you can realistically achieve with your equipment.

We have made a simple total station accuracy calculator below that should help with working these figures out.

### Guidance

• Start by looking up your equipments data sheet. Example: Leica TS15
• Refer to the relevant figures in the datasheet and fill out the values in the calculator.
• Lookup the prism datasheet you are using and add this into the centreing accuracy field.

In this example we are going to use a Leica TS15 1 second instrument. An example datasheet can be found here.

The first field we need to fill out is the “Accuracy [Hz] or [V]”. This can be looked up from your datasheet and is the horizontal and / or vertical accuracy of your total station.

Usually this is an easy figure to know as if its a 1 second machine it will be a 1 second horizontal / vertical accuracy. In the TS15 example you can see the field “Accuracy, HZ, V1” and the various figures for the different accuracy grade instruments.

The second and third fields to fill out are “Measurement Settings Accuracy (mm)” and “Measurement Settings Accuracy (ppm)” . This figure is dependent on the type of prism and setting you are using. For example in our example, if you are using a fast prism the value would be 2mm + 1.5 ppm. If you are using any surface (the laser) it would be 2mm + 2ppm.

The fourth field is the “Prism Centring Accuracy (mm)” This can be 0 if you are using a reflective tape or reflectorless measurements (laser). When using prisms look up the datasheet for the prism you are using. Here are the accuracies for various Leica prisms.

The last field is the sample distance. This is the maximum distance you are looking to calculate your tolerances for. In principle, the longer the distances the more your errors are going to be! In our example this is 1000 metres.