WL650 Sonic Water Level Meter
Sonic Water Level Meter Product Description
Global Water's WL650 Sonic Water Level Meter is a self-contained, battery-operated meter that uses sound waves to measure well water level. Fast, accurate measurements are possible in the field without using down-hole water level meters. The Sonic Water Level Meters, are lightweight, compact, versatile, and easy to operate.
The water level meter allows you to measure crooked wells, wells with cascading water, partially cased rock wells, wells with submersible pumps, capped or uncapped wells, and wells with pipes with wires inside. You can even measure the length of the spiral pipe with the water level meter. As long as the obstructions take up no more than half of the bore area, the meter will not suffer any loss of accuracy. A sonic water level meter must only be used on wells under 10 inches as the accuracy decreases with larger diameter wells.
Sonic Water Level Meter Operation
The WL650 Sonic Water Level Meter is simple to operate. Select the NORMAL (10-500 feet) or DEEP (200 to 1,200 feet) setting on the DEPTH switch. Then, insert the duct into the 5/8 inch broad access port to measure a capped well and push the power-on switch. The water level will appear on the water level meter's digital display in a few seconds. The sonic water level meter stays activated for 5 seconds or five pings in the NORMAL setting. The water level meter emits four pings in 16 seconds when using the DEEP mode. Hold the sonic water level meter's switch down for a more measuring time as long as necessary.
Ignore distance feature
The factory distance default values for the sonic water level meter are 10 ft ( 3 meters) in Normal mode and 200 ft (60 meters) in Deep mode. Suppose problems occur due to liner reflections that don't come to the top of the casing or unwanted signal returns from such things as pitless adaptors that interfere with getting a proper reading. In that case, the water level meter's default values can be increased so that returns within that distance are ignored. If you are making draw-down measurements that require the use of the sonic water level meter's deep mode, but you wish to be able to measure to less than 200 ft (60 meters), you can reduce the minimum distance accordingly so that you don't have to switch modes during the test.
For uncapped wells, use the provided cover plate, which slips onto the measuring duct and provides a seal for up to 6-inch diameter casings.
Gain/Sensitivity - ''Which Gain Setting to Use, Fixed or Variable?''
The Variable gain mode provides, in effect, a rising gain or sensitivity with time. This method gives greater weight to return signals that occur later in the measurement cycle and is beneficial on deeper wells where the return signal is more attenuated.
The Variable gain mode is somewhat more susceptible to interference from pump noise or other sources of high ambient noise. Also, in some specific configurations, the unit can favor a secondary return over the primary one and give a reading twice the actual water level.
The Fixed mode is less susceptible to interference from ambient noise and the secondary return problem. Some sensitivity is sacrificed, so the unit might not read the deepest water levels in this mode.
Temperature Control
Obtaining an accurate measurement with the sonic water level meter requires that the temperature setting on the meter be equal to the average air temperature inside the well casing. The sonic water level meter's temperature toggle switch adjusts the temperature setting for the sound velocity variation in the well casing. The temperature setting corrects the sound velocity variation with the well bore's air temperature.
The correct temperature setting can be determined by using the TEMPERATURE MAP TABLE provided with the water level meter for the state where the meter will be used (temperature settings are provided for all states in the United States). Alternatively, the reverse side of the map table has a LOOK-UP TABLE giving the setting if the well water and average monthly surface temperatures are known.