Clinometer

A clinometer also known as an inclinometer is an instrument for measuring angles of slope (or tilt), elevation or inclination of an object with respect to gravity. Also known as a tilt meter, tilt indicator, slope meter, slope gauge, gradient meter, gradiometer, level gauge, level meter, pitch & roll indicator.

The earliest clinometers used a weight, an extension, and a potentiometer. Early in the 1900's (circa 1917) precision curved glass tubes filled with a damping liquid and steel ball were introduced to provide accurate visual angle indication. Common sensor technologies for electronic tilt sensors and inclinometers are accelerometer, liquid capacitive, electrolytic, gas bubble in liquid, and pendulum. Moving forward, MEMs (Micro-Electro-Mechanical Systems) technology is becoming the newest type due to their tiny size and low cost.

Certain highly sensitive electronic inclinometer sensors can achieve an output accurate to .001 degrees. However, an inclinometer sensor's true or absolute accuracy (which is the combined total error) is a combination of initial sets of sensor zero offset and sensitivity, sensor linearity, hysteresis, repeatability, and the temperature drifts of zero and sensitivity - electronic clinometers accuracy can typically range from .01º to ±2º depending on the sensor and situation. Typically in room ambient conditions the accuracy is limited to the sensor linearity specification.

Examples Of Usage

Clinometers are used for:

• indicating pitch and roll of vehicles, sail boats, and aircraft.
• Monitoring boom angle of cranes and material handlers.
• Measuring the "look angle" of a satellite antenna towards a satellite.
• Measuring the slope angle of a tape or chain during distance measurement.
• Estimating the height of a building, tree, or other feature using a vertical angle and a distance (determined by taping or pacing).
• Measuring the angle of drilling in well-logging applications.

Factors Which Influence The Use Of Clinometers

(Overall accuracy varies depending on the type of inclinometer and technology utilized)

• Gravity
• temperature (drift), zero offset, linearity, vibration, shock, cross-axis sensitivity, acceleration/deceleration
• A clear line of sight between the user and the measured point is needed.
• A well defined object is required to obtain the maximum precison.
• The angle measurement precision and accuracy is limited to slightly better than one degree of arc .

Survey Methods Used For

• Clinometers are used for the measurement of angles in reference to gravity.
• The USDA Forest Service uses clinometers to measure tree height in its Forest Inventory and Analysis program.

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