Material-level sensor

Microfluidic velocity sensors are based on very sensitive structures and materials. Their sensor systems are developed using complicated fabrication technology and sophisticated measuring apparatus and at high production cost [10]. These are issues that require immediate attention because their commercialization is problematic. Microfluidic systems will achieve their full potential if micropumping operates at an optimum level where flow rate must be measurable and controllable based on the needs of the system. For an application that delivers protein to a microbioreactor at a precise rate using this micropumping operation, then some feedback... 

This chapter presented a concept drawing of a distillation process that included flow rate sensors, liquid level sensors, temperature sensors, and process control valves. The process streams were identified and labeled. The standard definition of reflux ratio was presented, and the concepts of separation power and material balance split were introduced. 

Another important class of titanates that can be produced by hydrothermal synthesis processes are those in the lead zirconate—lead titanate (PZT) family. These piezoelectric materials are widely used in manufacture of ultrasonic transducers, sensors, and minia ture actuators. The electrical properties of these materials are derived from the formation of a homogeneous soHd solution of the oxide end members. The process consists of preparing a coprecipitated titanium—zirconium hydroxide gel. The gel reacts with lead oxide in water to form crystalline PZT particles having an average size of about 1 ]lni (Eig. 3b). A process has been developed at BatteUe (Columbus, Ohio) to the pilot-scale level (5-kg/h). 

Contact temperature measurement is based on a sensor or a probe, which is in direct contact with the fluid or material. A basic factor to understand is that in using the contact measurement principle, the result of measurement is the temperature of the measurement sensor itself. In unfavorable situations, the sensor temperature is not necessarily close to the fluid or material temperature, which is the point of interest. The reason for this is that the sensor usually has a heat transfer connection with other surrounding temperatures by radiation, conduction, or convection, or a combination of these. As a consequence, heat flow to or from the sensor will influence the sensor temperature. The sensor temperature will stabilize to a level different from the measured medium temperature. The expressions radiation error and conduction error relate to the mode of heat transfer involved. Careful planning of the measurements will assist in avoiding these errors. 

A problem common to electrochemical cells is the analyzer can fail (degradation of the anode material and electrolyte or loss of sensor sensitivity), but still indicate a safe oxidant level when in reality it may not be so. Adherence to the manufacturer s recommendation as to how... 

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