Ultrasonic Laser Point LED Distance Measure Meter Tool(Blue)

1) Taking a measurement
Press MEASURE to turn on the unit. The measurer beeps then the distance between the measurer and the point you measured appears.
Hold the bottom of the measurer flat against a wall, about halfway between the floor and ceiling. Be sure there is a clear path to the point you want to measure and that your head or hands do not block the front of the measurer.
Repeatedly press FEET/METER until FEET appears (to measure in feet ) or until METER appears (to measure in meter).
Press and hold down MEASURE to take a continuous measurement.
2) Stabilizing the measure
Your measurer is sensitive to changes in temperature and humidity. Before you use the measurer, wait about 15~30 minutes for it to stabilize to the current room��s temperature.
3) Measuring Tips
Some types of curtains and blinds can absorb sound waves, causing measurements to be inaccurate. If you are measuring distances in a room with curtains, open the curtains before measuring the distance to a window behind them. Also, be sure that the window is closed.
If there is not a clear path between the points where you are measuring, you might receive a false reading from sound waves bouncing off objects such as chairs, tables and objects with uneven surfaces. If you are not sure if a measurement is correct, move slightly to one side then measure the distance again.
If the surface of a wall you are measuring is not solid and flat, of if you are measuring in a narrow corridor, you might receive a false reading. If this happens, use a solid surface to measure or move to the center of the corridor.
To measure a distance longer than 60 feet (18.288meters), select a point in the middle of the room (for example), measure from the center of the room toward each side, then add the two measurements.
4) Calculating volume
To find the volume of a room, measure the height, width and the length of the room and store each measurement in a different memory location (see "Saving a Measurement"). Then press VOLUME, the volume calculation result appear.
5) Calculating area:  
Follow these steps to find the area of any two stored measurements.
Measure the width and length of a room and store the measurements in M1 and M2 (see "Saving a Measurement").
Press AREA, M1, and M2, the area calculation appear.
6) Adding/subtracting stored measurements 

Measure any two dimensions of a room and store the measurements in memory locations 1 and 2 (see ��Saving a Measurement��)
Press ALL MEMORY CLEAR.
Press M1, +, M2, then + to add the measurements, or M1, -, M2, then to  subtract them. The value of the calculation appears. To clear the display and do another measurement, press ALL MEMORY CLEAR.