GPR1 Corner Cube Surveying Reflector Prism 2.0mm Centering Copper Coated

Corner Cube Surveying Reflector Prism GPR1

Model: GPR1

Description:

The GPR1 is Leica’s standard round prism, and is arguably the finest surveying prism made today.

The Leica GPR1 Single Circular Prism is a precision round prism that easily snaps on to prism poles. It features a centering accuracy of 2.0 millimeters with zero millimeter offset. The GPR1 is manufactured from high-quality optical glass for increased range and accuracy.

This Leica round prism’s surface is coated with anti-reflection copper which also improves reflectivity and prevents adverse dirt or condensation.

It is compatible with Leica GLS111 reflector poles and perfectly fits the Leica GPH1 and GPH3 round prism holders.

Introduction:

• 62 mm diameter
• 0 mm offset
• 2.0 mm centering accuracy
• Anti-reflection copper coating
• High-quality optical glass
• Compatible with Leica GLS111 reflector poles
• Fits Leica GPH1 and GPH3 round prism holders

Selecting a Surveying Prisms

When selecting a Surveying Prism, consider the offset, the thread size, and the size of the prism itself. When working with Total Stations that require a target or reflector, a Surveying Prism is a must-have. Some Prisms are used on the top of a Prism Pole, while some are made to be mounted to the top of a Tripod. Most Surveyors Prisms have a 5/8 x 11 thread size although some use adapters instead of threads such as the Leica / Swiss-type adapter. Mini stake-out type prism is smaller in diameter which allows the user to get close to a wall or building to get the shot or stake out.

Reflector Centring Accuracy

Measurement errors occur if poor quality prism holders are used. The holder and the prism constitute a unit with which the centring and repeat accuracy is defined. The smallest dimensional change in the geometry of a glass prism or on the holder can lead to a deviation from the centring axis and thereby create measurement errors.

Prism Range
The beam deviation of a prism defines the its maximum range, according to the principle "entering beam should equal the exiting beam". The smaller the beam deviation (measured in angle seconds), the greater the directly reflected signal strength to the sender optic. The returned signal quality defines the maximum range of a measurement.

Prism Measuring Accuracy

The range of a prism results from, among other things, its coating and the glass geometry. Measurement errors occur frequently at close ranges when prisms without anti-reflex coating are used, as the front of a prism always directly reflects a certain percentage of a signal. Errors occur in the use of prisms without copper coating on the back side when moisture droplets accumulate or the prism becomes foggy.

High standard quality prisms have a special coating on the reflective surfaces – the Anti-Reflex Coating, and a copper coating on the reverse side. Without these, the range of distance measuring, ATR and Powersearch would be reduced by up to 30%.

The workmanship and the durability of the copper coating are decisive for a long life.

The glass dimensions, the position in the holder and with it the areal orientation, are important for measuring accuracy.