Multi-Channel, Microwave-Based, Compact Printed Sensor for Simultaneous and Independent Level Measurement of Eight Liquids

Abstract

Industrial automation relies on sensing the process parameters like liquid levels. Simultaneous sensing of multiple fluids is especially useful for many automation processes involving multiple ingredients. Some of the desirable features in any level sensor are its non-intrusiveness, high accuracy and consistent performance. These features can be achieved with typical microwave radar based level sensors. However, this paper presents a microwave resonance method instead of typical microwave reflectance (radar) to reliably sense the liquid level at fraction of the cost using a unique printed sensor. In addition to that, sensor design presented in this article enables sensing liquid level of 8 liquids simultaneously and independently utilizing its multiple channels. An array of eight modified microwave Tresonators has been compactly packed inside a metallic cylinder of just 4˝ diameter where the resonators share the same ground plane. Sensors' performance, to measure the unknown level of eight different fluids (with dielectric constant (∈r) ranging from 2.8 to 80), has been measured in real time using a custom-built software. Simple one point calibration procedure has also been proposed in this paper which has resulted into measurement accuracy of ~0.6% which is better than 1%, realizable with highend and expensive radar based level sensors.

Perancangan dan Simulasi Sensor Volume Zat Cair berbasis Metamaterial Rektangular

“…Shalaev dan Cai [9] dan Abdulkarim dkk [10] melaporkan metamaterial dapat digunakan untuk mendeteksi zat seperti padat atau cair. Banyak peneliti memanfaatkan gelombang mikro sebagai frekuensi kerja sensor karena mampu mendeteksi kosentrasi larutan cair yang akurat, tidak merusak dan ekonomis [11,12]. Keunggulan metamaterial yang menarik adalah desain struktur yang sama dapat digunakan untuk beberapa fungsi sekaligus, misalnya detektor dan antena sekaligus [13], hanya diperlukan penyesuaian ukuran struktur dan jenis material.…”

UHF-band Solid Sensor Based on Tweaking Electric Field Coupled Resonator for Material Characterization

“…M aterial characterization plays an important role for several applications such as the pharmaceutical, biomedical, and materials industries [1,2]. Material characterization is very useful for knowing the ability and interaction of the material with changes in the surroundings, such as permittivity [3,4].…”

Microstrip-Line Sensor for the Estimation of the Fluid Level Inside a Closed Metal Pipe

“…The reflector-type sensors utilizing ultrasonic waves, microwaves, and lasers are highly susceptible to interference from the liquid environment. In addition, measurement errors may occur with ultrasonic sensors due to the effects of surface bubbles, while the signal-to-noise ratio of optical sensors such as lasers may be negatively affected by the atmospheric conditions such as dust in the empty space within a pipe [17]. Microwave radar-based sensors are not well-suited for fluid measurement due to their intrusive structure and the potential accuracy reduction caused by possible distortion in the progressing mode [18].…”