| 摘要 |
PROBLEM TO BE SOLVED: To obtain the density of solid matter and suspended matter in an object to be measured with high accuracy in real time by providing a phase difference measuring means with a phase counting means to count phase differences at a center location. SOLUTION: An oscillator 11 for reference generates micro waves of a frequency f+Δf different byΔf from the frequency (f) of micro waves from an oscillator 3 as a reference signal 13 in synchronization with a reference signal 2 from a clock source 1. A mixer 14 mixes a received signal 12 with the reference signal 13 to obtain heterodyne output of a frequencyΔf. A comparator 16 receives the input of heterodyne output 15 and outputs a measured digital signalθFB 17. A phase difference measuring means 18 is provided with a phase counting means to count phase differences at the substantially center location of phase differences, compares the measurement digital signal 17 with the reference signal 2 from the clock source 1, measures their phase difference, and outputs a phase differenceΦ. A computing device 19 computes the density of an object to be measured from the phase differenceΦfrom the phase difference measuring means 18 and outputs it. |
