WORKING GROUP 1 
HEMPENIUS 
49 
ITC DELFT SPECIFICATIONS FOR MIRROR STEREOSCOPES PHYSICS SECTION '62 
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Operation and Handling 
Eyepiece position . 1: angle with horizon a 0 
(exit pupil) . 2: height above table cm 
Adjustment of eyebase : ease of handling (h=hand; t=turn) .... 
: calibration in mm 
Focussing : ease of handling 
: calibration in dioptre 
Changing Magnification : with -► without binocular . • . . 
: binocular Mi -» M2 
Position of Prints within easy reach and sight 
Scanning in order to observe different areas 
Free space on table . 1: between leg and "optical axis" . . . cm 
. 2: between mirror and print cm 
. 3: between table-edge and leg cm 
Parallax adjustment : ease of handling. 
: calibration for zero-setting 
Dove prism : ease of handling 
Mechanical Asoects Tested subiectivelv on a comoarative basis 
Stability against vibration: when adjusting a knob 
: when moving or scanning 
: when changing magnification 
equiped with adjustable leg for levelling 
Protection against rough handling: of the mirrors 
: of other optical parts 
: of critical mechanical parts 
Protection against : dust and smoke when in use 
: dust and smoke when not used 
: humidity 
Good Tolerable Poor 
40-50° 
*32 
1 h; 11 
yes 
1 turn 
not 
1 handling 
1 handling 
easy 
1 handling 
> 26 
> 15 
> 35 
1 hand 
yes 
1 hand 
30-60° 
depends on a 
2 h; //slide 
obscure 
acc. + 5 
2 handlings 
2 handlings 
moderate 
2 handlings 
26-23 
10-15 
25-35 
2 hands 
2 hands 
> 70° 
etc. 
no 
2 hands 
not acc. 
3 handlings 
3 handlings 
hard 
legs on print 
< 23 
< 10 
< 25 
shift of print 
no 
Front 
■30 cm 
View 
Side 
View 
- 20 
10 
10 c 
n 
2 
0 
3 
0 
4 
0 
5 
6 
0 
2 
1 
0 
Complicated or simple construction and use: Spare parts: 
detachable accessories: 
Weight of stereoscope kg; of stereoscope + case kg. 
Size of case x . . . . x . . . . cm 3 ; Quality: 
Other accessories: Maintenance: 
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Points of wear and tear: mechanical: 
Optical: 
Expected Life: 
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Use: Short or prolonged use per day; Laboratory + 
Office; Production Room; Educational 
use; 
Field use-Tropical or Moderate Zone. 
69 
Parallax Bar available: ; Quality: 
; Remarks: 
Economic Aspects: 
71 
Price of stereoscope D. G.: 
Price complete D. G. 
ITC 
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Delivery time : 
$ 
DELFT 
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Service 
DATE- 
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Constant Quality : 
Constant Design : 
SIGNATURE