เครื่องวัดความสูงต้นไม้ Haga Altimeter
The "Haga" altimeter measures the angle of elevation and indicates heights directly for various knwon horizontal distances or base lenghts.
Several scales are provided and engraved on a rotatable horinzontal bar.
The 5th is mostly used to determine the gradient in road construction.
The base lenght is selected by turning a knob. Through the window in the near side the markings of the base lenght scale in use are easily seen, the scale not in use being invisible, thereby eliminating any posibility of error in reading, while the speed of reading is increased.
Thus the instrument has all the advantages of multiple scales without the usual drawbacks.
The "Haga" altimeter can be used in feet, yard and metres. You only have to read the indicator on the scale in the same unit as you measure the base length.
The "Haga" altimeter takes place in a robust leathercase with carrying strap.