The phosphate content of a test sample is one of the indicators of the trophic status of the test water. In this work, an attempt was made to use a non-destructive ultrasonic technique to determine this parameter. For this purpose, a specially prepared measuring station was used, on which distilled water samples with different phosphate contents were tested. Specially prepared samples contained 0, 20, 40, 60, 80 and 100 kg/m3 of phosphates. In addition, tests were carried out on the effect of sample temperature on the values of the characteristic parameter of the wave, in the range from 12 to 30 oC. All tests were carried out using two ultrasonic heads with a wave frequency of 2 MHz. The ultrasonic wave parameter analysed in the study was the propagation speed of the ultrasonic wave.
The results obtained indicate that the ultrasonic method is useful for non-destructive evaluation of phosphate content in the sample. Additionally, they show a large influence of the sample temperature on the results read.