How to Use the Suunto Tandem Clinometer

How to Use the Suunto Tandem Clinometer

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Suunto opened its doors in 1936 when an avid outdoorsman got tired of not being able to purchase an accurate weatherproof compass. The Suunto Tandem is a combination clinometer and compass, and was designed for use by surveyors, engineers and other professionals who need the capability to measure direction, height, slopes and vertical angles. Proper use of the clinometer will allow for precise measurement of location and height of local objects.

Items you will need

  • Suunto Tandem

Hold the viewing lens to your right eye. Keep both eyes open while operating the clinometer. Each step will contain an example that follows taking the height measurement of a flagpole.

Aim the clinometer at the target object. Raise or lower the clinometer until the horizontal hairline on the left side of the scale is touching the point that is being measured.

In our example, line the horizontal hairline up with the very top point of the flagpole.

Hold the hairline on the object. Read the left hand scale to determine the slope in degrees from the horizontal plane. Read the right hand scale to give the height of the point in percent of the horizontal distance from the ground (eye level of the clinometer).

In our example, the left reads 25 1/2 degrees, and the right reads 48 percent.

Use the slope angle or height of point to determine the needed piece of information, or simply record your findings. If determining the height of an object, multiply the height of point (as a percent) by your distance from the object. This will determine the height of the object.

In our example, we have measured the distance between the flagpole and the clinometer using a long tape measure and found it to be 82 feet. The formula would be 48/100 x 82 = 39 feet. Then add the height from the ground to the clinometer at your eye. This will give the total height of the flagpole - in the example, about 44.5 feet (assuming eye level is 5.5 feet).


  • Be cautious when using the compass near any metal, as the reading can easily be effected.
  • Always keep both eyes open when using the clinometer, because it won't work correctly without a full range of vision.


  • Be sure that your Tandem is balanced to correspond to your home area. The balance is indicated by a number under the serial number -1 corresponds to most of the northern hemisphere. Without the proper balance, the compass will not work correctly.
  • Many methods may be used to determine the distance of the clinometer from the object measured, including measuring tapes and measuring and comparing the shadow.