Topcon RC-4 - Light Emitting Angle; Aiming Importance for Turn-round

Basic Operation
17
Light Detecting Range
The detecting angles of RC-4R and RC-4H (TS/IS/QS) are shown below:
TS/IS/QS can only be turned round with the turn-round key under the condition that RC-4R remains confined
within the range as shown below where RC-4H can detect light.
Important
Maintain the angle toward the TS/IS/QS within the range shown above until
the turn-round function is completed.
Turn-round function can be done within above range.
Top view
Side view
Detecting range
Detecting range
(RC-4H can detect the laser in all horizontal direction.)
RC-4H