Abstract: An electronic level for receiving a reflection light from a pattern marked on a leveling rod and for determining a height of sighting position and a distance to the leveling rod is disclosed. The electronic level comprises an electronic level main unit, a sighting optical system accommodated in the electronic level main unit and for sighting the leveling rod, a line sensor for receiving a part of reflection light, and a control arithmetic unit for calculating a height of sighting position and a distance to the leveling rod based on signals from the line sensor. The electronic level has a crude measurement mode and a precise measurement mode, wherein the crude measurement mode is initiated by the control arithmetic unit, and the measurement mode is changed over to the precise measurement mode by detecting the pattern based on a photodetection signal from said line sensor by measurement.

Abstract: An apparatus for treating fuel vapor, such as in a motor vehicle fuel tank, by subjecting it to adsorption treatment to prevent its direct emission into the atmosphere. The apparatus according to the present invention comprises a fuel tank, a partitioning wall provided within the fuel tank to define a small fuel storage chamber within the fuel tank, a canister container housed in the small fuel storage chamber, the canister container storing therein a fuel adsorbing material. When fuel feeding takes place, feeding fuel is introduced into the small fuel storage chamber to cool the canister container. However, when the engine is operated, high temperature return fuel is introduced into the small storage chamber to heat the canister container thereby promoting the adsorbing and de-adsorbing action of fuel by the fuel adsorbing material.