Untitled - MendelNet 2013 - Mendelova zemědělská a lesnická ...

MENDELNET 2013INTRODUCTIONThe thermodynamic sensors (TDS) can be used for monitoring and characterization of thermalprocesses in thermodynamic systems. The basic idea, basic model and theory of idealthermodynamic sensor integration as an ideal element in large models of thermodynamic systemwere presented in patent (Anonym, 2001). The original theory of ideal thermodynamic sensor as aprocess and media energy activity monitoring device was presented in (Reznicek M., Szendiuch I.,2005, Reznicek Z., et al., 2005, Reznicek Z., et al. 2006). The principle of thermodynamic sensorsis based on measurement of energy, which is supplied to circuit to temperature setting andequilibration of temperature element with ambient. The sensor element is very often integrated withan amplifier and a converter to defined electrical signal (U, I, f), which is very easily connected toother measuring systems. High speed and sensitivity are the main advantages of thermodynamicsensors over other temperature sensors' types, for example thermocouples.The basic idea of thermodynamic sensor is possible to use in various applications. Some groups ofinfluences have effect on TDS, fig.1. First group of influences is presented by influences I1, whichonly have effect on a temperature of sense element T2. Various physical quantities (temperature,radiant heat, humidity, flow of liquid), which are possibly transformed to temperature energy, aretheoretically measured in this group. Second group of influences is presented by influences I2,which change the temperature properties between the sense elements T1 and T2. In this group, thephysical quantities as volume, density, flow of liquid, pressure, … are theoretically measured. Lastgroup of influences is presented by influences I3, which have effect on a temperature of both senseelements T1 and T2. This group does not have effect on output signal of thermodynamic sensor.Fig. 1 The group of influences, which have effect on TDS.Because the TDS are very sensitive and fast, it is possible to measure very small temperaturechanges that may be produced for example by yeast. It is therefore possible to use TDS in the foodindustry in• dairy products - fermentation processes, yogurt processes, renneting processes,• breweries - fermentation processes,• distilleries - fermentation processes,• bakeries - controls vitability of yeast,• control unwanted development of yeast and other microflora (sterilization, canning)• pickled cabbage - fermentation processes, etc.551 | P age