INVICTA MK1 Clinometer User Guide

: June 3, 2024
: INVICTA

Table of Contents

INVICTA MK1 Clinometer
- NOTES ON THE USE OF THE ‘INVICTA’
OPERATING INSTRUCTION
MEASURING ANGLES OF WALLS, FLOORS AND SLOPES
References
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INVICTA MK1 Clinometer

INVICTA-MK1-Clinometer-PRODUCT

NOTES ON THE USE OF THE ‘INVICTA’

CLINOMETER: This is a very practical device of extreme simplicity and accuracy for measuring the angle of elevation required to find heights or depths of buildings, hills or valleys. Having found the angle of elevation, the actual height of the object viewed may be found by scale drawing or by application of simple trigonometry. This Clinometer, by its simplicity, brings such an exercise within the scope of the junior school and yet is sufficiently accurate for sixth-form work.

OPERATING INSTRUCTION

The Clinometer should be held like a target pistol with the arm outstretched (elbow straight – not bent), with the forefinger on the trigger. It should be pointed at the top of the object to be sighted and the trigger pressed, and held pressed, until the graduated disc becomes stationary. The trigger is then released and the Clinometer can then be brought down from the aim position and the angle of elevation can be read. Care should be taken not to touch the trigger again or the reading will be affected. The whole operation takes only a few seconds. The only possibility of inaccuracy is in the operator’s steadiness in ‘shooting’. For this reason, it is recommended that a check reading should be made. An inaccuracy of one or two degrees can make quite a difference to the final answer.

WARNING

NOT SUITABLE FOR CHILDREN UNDER 36 MONTHS BECAUSE SMALL PARTS MAY CAUSE A CHOKING HAZARD. TO BE USED ONLY UNDER ADULT SUPERVISION. Please retain the information from this pack for future reference. We reserve the right to alter designs and specifications (including colours and materials) when such changes are unavoidable. This product conforms to the safety requirements of EN71, ASTM, 16 CFR and The Canadian Hazardous Products (Toys) Regulations.

INVICTA-MK1-Clinometer-FIG-1

It will be seen from Fig. 1 that any calculation of height is from the eye level (A-B) of the operator. The height of the operator to eye level should be added to the distance above eye level. If the ground level undulates or slopes, a horizontal sight can be taken with the Clinometer. The distance of the operator from the object does not matter except that is must be known.

EXAMPLE 1: TO FIND THE HEIGHT OF THE BUILDING

Reading on Clinometer = 17°
Distance from building = 60m
Height of operator to eye level = 1.52m

A scale drawing of 1cm for 2m gives 18m for the height. Add the operator’s height up to eye level, say 1.52m. The height of the building is 19.52m.
By trigonometry the height of the building = Base x Tan.17° + operator’s height to eye level.
- = 60m x 0.3057 + 1.52m
- = 6 x 3.057 + 1.52m
- = 19.86m

N.B: Either of these methods is within the range of a junior child.

INVICTA-MK1-Clinometer-FIG-2

There is a school of thought which would recommend Junior children making use of the formula: Height = Distance x Tangent of the angle without necessarily understanding all the mathematical concepts involved. If the distance from the object can be chosen in simple figures (e.g. 100m) then the calculation of the height is a very simple one (100m x Tan.) On the other hand, scale drawing appeals to the less mathematically-minded and is good preliminary experience for more abstract work at a later stage.

EXAMPLE 2: TO SURVEY A STRETCH OF COUNTRY WITH INTERESTING CONTOURS.

A team of six might undertake this project. No. 1 operates the Clinometer; No. 2 does the recording; Nos. 3 and 4 use the chain or tape measure; Nos. 5 and 6 ensure that direction is maintained, using compass and poles or ‘Invicta’ ranging poles. The letters A to E show points where angles of elevation are ‘shot’. IT WILL BE NOTED THAT THE ‘INVICTA’ CLINOMETER MAY BE AIMED DOWNWARDS (A-B) AS WELL AS UPWARDS.

The team returns with distances and angles from A to E. A scale drawing is made. A length of string gummed to the paper and various recognition symbols such as trees, farmhouses etc., make an impressive wall display. As this exercise involves no calculation, it is excellent for developing spatial concepts.

MEASURING ANGLES OF WALLS, FLOORS AND SLOPES

A. Check vertical surfaces.
- A zero reading shows that the wall is vertical.
B. Check horizontal surfaces.
- A zero reading shows that the table top is horizontal.
C. Check angle of inclined surfaces.
- Read off angle of slope at arrow.