A Citric Acid Concentration Detector Used With Chicken Poultry Drinking Solution

In this paper, a citric acid concentration detector was newly used with chicken poultry drinking solution. It consisted of a citric acid sensor and a proposed citric acid concentration sensor transducer. The proposed citric acid concentration sensor transducer can linearly convert citric acid concentration into a duty cycle output. Compared with the traditional analog outputs, the proposed detector could have less noise sensitivity due to its digital output. Moreover, an adjustment technique to vary the input currents of the proposed sensor transducer is also presented. The functionality matching the different current ranges of other citric acid sensors could thus be easily achieved. All functions of the citric acid sensor and proposed citric acid concentration sensor transducer were verified through measurements. The measured input current dynamic range of the proposed sensor transducer was from 0.1 μA to 8.77 mA (i.e., 98.86 dB). The citric acid concentration ranged from 1% to 15%, with the corresponding duty cycle ranging from 51.3% to 96.3%. The maximum linear error measured was 0.28%. Sensitivity was measured at 3.2%/%, and the chip area was 1.49 × 1.49 mm
²
. Finally, an experiment for detecting the citric acid concentration of chicken poultry drinking solution was conducted, proving that the proposed chip was suitable for citric acid concentration detection.