Crown CT44043 Original Instructions Manual page 3

III. Measuring method
1.Height measurement
(1)Set up the instrument between A and B.
(2)Vertically set up the staff at A,
the height reading is a.
(3)Vertically set up the staff at B,
the height reading is b.
(4)The reading of height distance
between A and B is a-b
(Fig.5) h=a-b
=1.735-1.224
= 0.511m
2.Distance measurement
(1)Point the staff, get the reading between
upper & lower stadia hair, unit is "cm"
(2)Then the distance from the instrument
to the staff equals to ℓ unit is "m".
(Fig6.7)length of ℓ is 32cm,that is the
distance from instrument to staff is 32m.
3.Angle measurement
(1)Sight A with vertical hair, read circle,
get angle α.
(2) Turn instrument to sight B, get angle β.
(3)<AOB=α-β (Fig.8)
IV. Checking and adjusting
1.Circular bubble checking
(1)Turn footscrews to centre the bubble.
(2)Turn the instrument 1800,the bubble
shall be at centre.(Fig.9) otherwise it shall
be adjusted. The method is as following.
(I)Turn footscrews, making the bubble
halfway to centre.(Fig10)
(II)Using wrench adjust bubble screws to
move the bubble to centre. (Fig.11)
hair cross
stadia hair
footscrews
English
3
(3)Repeat (I)(II) until the bubble stays at
the centre when the instrument is turned to
any directions.
2.Horizontality of the line of sight
(1)Set the instrument halfway between A
and B, staff A and B shall be 30~40M away,
the readings are a1,b1(Fig.12)
Fig.5
(2)Move the instrument 2m away from A,
the readings are a2,b2(Fig.13)
(3)Calculate b2'=a2-(a1-b1).If b2'=b2, it
Fig.6 shows that line of sight is no need to
correct.
(4)If b2'≠ b2,it shows that correction shall
be needed.
(5)Point the optical sight to staff B,screw
off the eyepiece cover, adjust the screw of
cross-hair to make middle hair give the
required reading b2'.
Fig.7
(6)Repeat the above until ▏b2'- b2 ▏
<3mm。
Fig.8
V. Maintenance of instrument
In order to protect all parts and not lose its accuracy, care must be taken.
1.After the surveying operation, the instrument should be cleaned and kept in the container.
Fig.9
2.Use soft brush, lens paper to wipe lenses. Do not use finger to touch lenses.
3.If the instrument has something wrong or damaged, it must be checked and repaired by technician
or skillful person, or have it repaired by the manufacturer.
4.There is a bag of drier in the container. If it has lost efficiency, bake it or change new one.
5.The instrument should be stored at a dry, clean and good air condition place.
Note:400gon circle, 5/8" tripod are for export.
Detail
Carrying case 1
Auto- level 1
Fig.10 Adjusting pin 1
Allen wrenc 1
bubble screws
User guide 1
Plumb(additional) 1
Drier 1
English
4
Fig.11
Fig.12
adjust screws
Fig.13