inclinometer; tiltmeter; angle meter
Technical instrument for measuring slope, tilt, or inclination, used in surveying, engineering, and geology.
We installed an inclinometer to monitor landslides.
This tiltmeter can measure even small tilts.
A general angle gauge; 傾斜計 is more specific to slope or tilt measurement.
Compound of 傾斜 (keisha, 'inclination') + 計 (kei, 'meter, gauge').