Accoustical apparatus and method for measuring water level in a ground water well

A method of measuring the level of the surface of water in a ground water well using a sonic acoustic pulse emitter having a vibration factor (W) and a sonic pulse receiver, said well having an axis, and an inside diameter θ, wherein said level is measured as a function of the distance D between said emitter and said surface, and further wherein the surface has a minimum distance from the emitter of DMIN, said method comprising the steps of:

• a. transmitting a single pulse of sonic acoustic energy down said axis of said well wherein said pulse of sonic energy will create a plurality of reflected pulses R1 to RN having respective amplitudes AR1 to ARN;
• b. receiving a first reflected pulse R1;
• c. measuring the time-of-flight (tf) of said first reflected pulse R1;
• d. repeating steps b and c for each pulse of said plurality of reflected pulses R2 to RN;
• e. combining said time-of-flight measurements (tfavg)for each of the plurality of reflected pulses R1 to RN;
• and,
• f. calculating D using the relationship D=S(tfavg)/2 where S is the speed of sound.

A method of measuring the level of the surface of water in a ground water well using a sonic acoustic pulse emitter having a vibration factor (W) and a pulse receiver as a function of the distance D between said emitter and said surface of water, wherein said well has an axis and an inside diameter (θ) said method comprising the steps of:

• a. transmitting a first pulse of sonic acoustic energy having a frequency f1 down said axis of said well thereby creating a plurality of first reflected pulses R11 to R1N;
• b. receiving at the sonic receiver a first reflected pulse R11 of said plurality of first reflected pulses R11 to R1N;
• c. measuring the time-of-flight (t1f1) of the said reflected pulse R11;
• d. repeating steps b and c for each of the subsequent reflected pulses R12 to R1N;
• e. recording the time-of-flight measurements t1f2-N for each of the plurality of first reflected pulses R12 to R1N;
• f. calculating the average time-of-flight measurement (t1favg);
• g. calculating a first value for D1 using the relationship D1=S(t1favg)/2 where S is the speed of sound.

An acoustic distance measuring device for measuring the level of water in a ground water well, wherein said well has an axis, a diameter (θ) and a water level measured as a function of the distance (D) from said device to said water level, wherein said distance D varies between DMAX and DMIN, and further wherein said acoustic distance measuring device comprises:

• a. an electrical circuit adapted to generate an electrical signal of having an initial amplitude (Ai) and a frequency (f);
• b. a sonic pulse emitter coupled to said electric circuit and adapted to convert said electric signal into a sonic pulse having a frequency (f) and an amplitude Ai wherein, said sonic pulse emitter is co-axial with the ground water well and has a vibration factor W, and further wherein the sonic pulse emitter is adapted and oriented to emit a sonic pulse down the axis of the ground water well thereby creating a plurality of reflected pulses R1-RN;
• c. a sonic pulse receiver proximate to said sonic pulse emitter, wherein said sonic pulse receiver is adapted and oriented to receive said reflected pulses R1-RN each having an amplitude AR1 to ARN respectively, and wherein said sonic pulse receiver is adapted to generate an electrical signal having a strength relative to the amplitude AR1 to ARN of the reflected sonic pulses;
• d. a comparator circuit connected to the sonic pulse receiver for comparing the amplitude AR1 to ARN of the received reflected sonic pulse with a predetermined threshold value ALIM, wherein said comparator is adapted to reject any amplitudes falling below ALIM, and further wherein the comparator adapted to convert analogue signals to digital signals for transmission to;
• e. a microprocessor connected to a programmable memory storing operating and application programs, wherein the microprocessor is adapted to executed said programs to calculate the time-of-flight (tf) of each of the said the emitted sonic pulses, and wherein said microprocessor is further adapted to calculate said distance (D) according to the relationship D=S(tf)/2 where S is the speed of sound.

A method of using an acoustic distance measuring device for measuring the level of water in a ground water well, wherein said well has an axis, a diameter (θ) and a water level measured as a function of the distance (D) from said device to said water level, and wherein said distance D varies between DMAX and DMIN, and further wherein said acoustic distance measuring device comprises an electrical circuit adapted to generate an electrical signal of having an initial amplitude (Ai) and a frequency (f);

• a sonic pulse emitter coupled to said electric circuit and adapted to convert said electric signal into a sonic pulse having a frequency (f) and an amplitude Ai wherein said sonic pulse emitter is co-axial with the ground water well and has a vibration factor W;
• and further wherein the sonic pulse emitter is adapted and oriented to emit a sonic pulse down the axis of the ground water well thereby creating a plurality of reflected pulses R1-RN;
• a sonic pulse receiver proximate to said sonic pulse emitter, wherein said sonic pulse receiver is adapted and oriented to receive said reflected pulses R1-RN each having an amplitude AR1 to ARN respectively, and wherein said sonic pulse receiver is adapted to generate an electrical signal having a strength relative to the amplitude AR1 to ARN of the reflected sonic pulses;
• a comparator circuit connected to the sonic pulse receiver for comparing the amplitude AR1 to ARN of the received reflected sonic pulse with a predetermined threshold value ALIM, wherein said comparator is adapted to reject any amplitude below ALIM, and further wherein the comparator is adapted to convert analogue signals to digital signals for transmission to;
• a microprocessor connected to a programmable memory storing operating and application programs, wherein the microprocessor adapted to executed said programs to calculate the time-of-flight (tf) of each of the emitted sonic pulses, and wherein said microprocessor is further adapted to calculate said distance (D) according to the relationship D=S(tf)/2 where S is the speed of sound, said method comprising the following steps:
• a. programming said application software by inputting values for W, θ, DMIN, DMAX and ALIM;
• b. selecting a mode of operation;
• c. calculating the low range of a first frequency f1LOW of a first sonic pulse to be emitted by the sonic pulse emitter;
• d. calculating the high range of a first frequency f1HIGH of said first sonic pulse to be emitted by the sonic pulse emitter;
• e. selecting a first sonic pulse frequency f1 for the first sonic pulse between f1LOW and f1HIGH;
• and.
• f. selecting amplitude Ai for the first sonic pulse.