Comments on “Development of an Intelligent Temperature Transducer”

In a recent work, (Narayana and Kumar, Development of an Intelligent Temperature Transducer, IEEE Sensors J., vol. 16, no. 12, pp. 4696-4703, 2016), an intelligent temperature-to-frequency converter (TFC) for thermistors, in an input temperature range of 0 °C-100 °C, has been reported. In this paper, a 555-timer based signal conditioning circuit (SCC) was employed as TFC. Linearity, between input temperature and output frequency, was further enhanced with an application of an artificial neural network (ANN). It is pointed out that this paper developed erroneous frequency expressions, waveforms, and non-functional SCC circuit in addition to the sensitivity of 5 kHz/°C. In this paper, based on mathematical formulations supported by Multisim™ simulations, errors of intelligent TFC are presented and required corrections are proposed for frequency expressions, waveforms, and sensitivities.