Before determining the instrument errors, the instrument has to be levelled using the electronic level. The tribrach, the tripod and the underground should be stable and secure from vibrations or other disturbances.
The instrument should be protected from direct sunlight to avoid thermal warming.
It is also recommended to avoid strong heat shimmer and air turbulence. The best conditions are early in the morning or with overcast sky.
Before starting to work, the instrument has to become acclimatised to the ambient temperature. Take at least 15 minutes into account or approximately 2 minutes per °C of temperature difference from storage to working environment.
Next step
• Adjusting a combination of instrument errors
Refer to "5.3 Combined Adjustment (l, t, i and c)".
• Adjusting the circular level
Refer to "5.4 Adjusting the Circular Level of the Instrument and Tribrach".
• Adjusting the laser/optical plummet
Refer to "5.6 Inspecting the Laser Plummet of the Instrument".
• Adjusting the tripod
Refer to "5.7 Servicing the Tripod".