@johnsold wrote:
mangood,
You can use standard values from handbooks. Any errors in your room will be much smaller than the one part in eight you mentioned in one of your earlier posts.
Ultrasonic distance measurements are based on the time it takes the sound to travel between two points so anything which affects the speed of sound in the air can change the result. According to a table on Wikipedia the speed of sound increases about 1% for a temperature change from 20 to 25 degrees C.
Lynn
thank you
hi ?Q>
