High performance conductivity monitoring instrument with pulsating sensor

Abstract

We present an unconventional but high performance pulsating conductivity monitoring instrument constructed by using a new class of sensor, viz., pulsating sensor developed in house. The design consists of a special type of logic gate oscillator (LGO) powered by 5 V direct current (dc). The conductivity cell constitutes a part of LGO. In this conductivity meter the primary signal generated from the sensor is directly in digital domain which is easily transmitted either to a personal computer or to a stand-alone embedded system. Hence it reduces the hardware components making the instrumentation highly simplified. The output of the instrument is pulse frequency which is directly related to the conductivity of solution used for measurement. The relation between pulse frequency and conductivity is determined following a multipoint calibration technique developed in our laboratory using a series of KCl standards. The performance of the instrument is demonstrated with a few examples which reveal the diverse application of this new approach of measurement technique.

Kinetic studies on saponification of ethyl acetate using an innovative conductivity‐monitoring instrument with a pulsating sensor

“…The precision in measurement is less than 0.7 Hz, and the resolution of instrument used for the present application is about 0.1 μS cm −1 . However, resolution can be further improved by slightly modifying the geometry of electrodes and the capacitive component of instrumentation [19]. The response time, which is defined as the time required by the instrument to respond 63% of a sudden change in signal, has been evaluated from this figure.…”

“…Using our indigenously made data acquisition system, the online data in graphic form are recorded and stored for future use. The detailed instrumentation, calibration technique, and the performance of this innovative conductivity meter have been described in one of our latest publications [19].…”

“…A pulsating sensor based conductivity monitoring instrument [19] was used in the present study. A verticaltype Teflon probe with a pair of platinum electrodes (platinum rods with 0.5 mm diameter, 5 mm length, 5 mm gap between electrodes) fixed onto the bottom of it was used for online monitoring of conductivity shift during kinetic experiments.…”

Numerical and Experimental Investigation of Air-Water System to Simulate Bubble Dynamics in Liquid Sodium Pool

“…A new class of digital sensors known as pulsating sensors has been developed and deployed in many physico-chemical applications (Sahoo et al, 2010;Malathi et al, 2015;Praveen et al, 2010). Unlike other conventional sensors, the primary electronic response of the sensors is in pulse form, i.e., in the digital domain, which avoids intermediate signal processing stages of pre-amplification, post-amplification, and analog-to-digital conversion.…”

Continuous-type liquid Level Measurement System using pulsating sensor

“…The digital pulse frequency is a function of the sensed parameter and this approach simplifies instrumentation of each sensing device. The sensors exhibit high resolution, high precision, excellent noise immunity, and low response time and deployed in a variety of applications such as monitoring high resolution measurement of conductivity [8], temperature, pressure, vacuum, liquid level, radiation dose, pH and emf of solutions etc. A high resolution differential pressure sensing device [9] has been developed in Innovative Instrumentation Section (lIS) for online measurement of differential pressure with a resolution of 0.1 mbar.…”