Leica T-Scan 5 User Manual

The adjustment (compensation) of the marker LEDs and of the reflector on
the T‑Scan determines the accuracy of the determination of the reflector
position.
Some of the parameters, which affect the accuracy:
•
Marker LEDs and their local coordinates
•
Local coordinates of the reflector
•
Height of the reflector and its index of refraction
•
X- and Y-rotation in local coordinates
•
Local X-, Y- and Z-coordinates of the T‑Scan
The infrared marker LEDs are placed on the T‑Scan with an optimal three-
dimensional distribution. Based on a specific adjustment (compensation) pro-
cedure, the position of the marker LEDs and the reflector in a common local
coordinate system (X, Y and Z) can be determined.
☞
Local coordinates refer to the coordinate system of the T‑Scan.
The reflector position on the T
‑Scan is determined by the relative position of
the marker LEDs. The accuracy of the reflector position depends on the fol-
lowing parameters:
•
Height of the reflector
•
Refraction index of the glass prism
•
Tilt angle of the reflector front to the X/Y-plane of the T‑Scan coordi-
nate system
The automated adjustment procedure uses these parameters to avoid sys-
tematic measurement errors.
4.3.2 Maximum Permissible Error (MPE)
Accuracy specifications in the technical data of this manual are stated with
the Maximum Permissible Error (MPE). The Automotive Society of Mechanical
Engineers (ASME) defines Maximum Permissible Error (MPE) as the "extreme
values of an error permitted by specification, regulations, and so on ... for a
given instrument". The ASME B89.4.19-2006 standard further expands this
definition by specifying that if during testing a corresponding measurement
fails to meet the MPE requirements, then the failed measurement is allowed
to be remeasured five times, with the magnitude of the largest error replac-
ing the failed position value. If the new value fails to satisfy the MPE require-
ment, then the test is allowed to be done a second time (but not more than
twice) with a failed result leading to a failed inspection test. Typical measure-
ment results of the Absolute Tracker are half of the relevant MPE values.
4.3.3 Measurement Uncertainty
The following specification of uncertainty is achieved with the Leica T‑Scan
under stable environmental conditions.
Coordinates of the
marker LEDs
Coordinates of the
reflector
Description
Specification of
uncertainty with
T‑Scan
30 Operation

Leica T-Scan 5 Specifications

General

Brand	Leica
Model	T-Scan 5
Category	GPS
Language	English