CN202305460U - Edible oil quality rapid detector based on dielectric property - Google Patents

Abstract

The utility model relates to an edible oil quality rapid detector based on the dielectric property. A cuboid detection instrument is formed by self-designed capacitive sensors, a signal converter, a micro control processor, a display, indicating lamps, a buzzer, power supplies and the like, wherein a mathematical model is embedded in the signal converter to carry out signal conversion; the capacitive sensors are parallel-plate electrode plates (the parallel-plate electrode plates are made of stainless steel materials with thicknesses of 0.1cm, plates have specifications of 9*9cm, and a parallel distance is 0.6cm); the micro control processor is an AT89S52 single chip microcomputer; batteries are four AA dry batteries; the display is an LCD liquid crystal display; and the capacitive sensors are placed into oil to be measured, parameter values of four indexes of a sample can be displayed after the operation of pressing buttons is carried out for 15s, and the selective alarm is carried out according to set values.

Description

Edible oil quality fast detecting appearance based on dielectric property

Technical field

The utility model relates to a kind of detecting instrument; Relate to a kind of detecting instrument that is used to estimate the edible oil quality specifically; Can demonstrate indexs such as acid value in the edible oil sample, iodine number, peroxide value simultaneously; And different according to the user to the demand of edible oil quality, edible oil index threshold values can be set voluntarily detect.

Background technology

Along with economic globalization process is quickened day by day, food security has had influence on international food and Agricultural Products Trade, becomes one of focal issue of international community's concern.Seeking novel, quality of agricultural product detection method quickly and accurately, is the logistics that develops rapidly in the modern times and the food security guarantee is long-term pays close attention to and problem anxious to be solved.China's edible oil seriously exists acid value, peroxide value exceeds standard; Dissolvent residual exceeds standard, edible oil is mingled, interpolation of swill oil and the excessive interpolation of edible additive, iundustrial oil, oil in bulk capsule contamination problem etc., directly has influence on the sustainable development of consumer's health and edible oil industry.

Evaluation method to the edible oil quality has had a lot of research reports, but does not also confirm the detection method that generally acknowledge in a kind of whole world, and also there are diverse ways and standard in different fields of employment.Like test paper method, coulometric titration, potentiometric titration, AAS, fluorescence method, liquid phase chromatography and polarography etc.; The subject matter that these methods exist has: sample pretreatment is consuming time like separation, extraction etc.; Equipment price is expensive; Organic reagent can not be applicable to that to adverse effect of environment and personnel health etc. modern society is to the food safety detection requirement.From general detection expand to fast, real-time online, high sensitivity, harmless, green be the direction of following detection technique development.

Present domestic testing agency or the used detecting instrument of manufacturer mainly contain following characteristics: function is perfect inadequately, and the detection index that has testing conditions single, that have is harsh; Price is very different, is difficult to accomplish the high performance-price ratio of detecting instrument; The good instrument of performance is generally large-scale, can't realize that function combines with easy to carry.Like near infrared rapid edible analysis of oil appearance, can accurately determine many indexs such as iodine value in the grease, free fatty acid, phosphorus value, but expensive, small product size is huge, and is not portable.

The DEVELOPMENT PROSPECT of the detecting instrument of convenient, simple, low-cost, many indexs is wide, and its applied range all has good practical value in enterprise, quality inspection organization.

Summary of the invention

For overcome existing chemical detection mode precision high but waste time and energy, deficiency that process is numerous and diverse; The utility model provides that a kind of capacitor type based on dielectric property is portable, measuring accuracy is high, edible oil Quality Detection appearance easily and fast, can calculate the concrete numerical value of acid value, iodine number, peroxide value, saponification number four indices automatically according to the capacitance of measuring.

The technical scheme that the utility model solves the problems of the technologies described above employing is:

A kind of edible oil Quality Detection appearance based on dielectric property; Insulation crust, signal converter, microcontroller processor, display, temperature sensor, alarm lamp, hummer are connected successively; There is capacitive transducer the outside, it is characterized in that: according to the characteristics of circuit, be digital signal with the capacitance simulation conversion of signals of testing in the signal converter---and be the square-wave signal of different frequency; One chip microcomputer is counted the frequency of input; According to different count results, computing draws each parameter of current oil to be measured, send display to show and also selects according to imposing a condition to report to the police.

Said test pole plate adopts the stainless steel of 9*9cm, and alternate 1cm is also connected by insulated connectors, and the test pole plate links to each other with 555 circuit of internal circuit; Embedded five buttons on the apparatus subject, control knob, four pilot lamp, a LCD, LCD types is 16*9cm, dark border, blue liquid crystal background.

Said capacitive transducer is the parallel plate electrode plate (stainless steel material of thickness 0.1cm, flat board is 9*9cm, parallel distance 0.6cm) that designs voluntarily; Described temperature sensor is a DS18B20 single bus digital temperature sensor; Described signal converter is the high precision capacitance measuring tester of developing with the square-wave generator that devices such as 555 counters constitute; Said microcontroller processor is the AT89S52 one chip microcomputer; Said battery is No. 5 dry cells of 4 joints; Said display is the LCD12864 LCD, 16*9cm, dark border, blue liquid crystal background.

The mathematical model that embeds in the said signal converter; Its principle of work is: the edible oil index of quality of measuring different disposal method and period of storage with national standard method; Like acid value, peroxide value etc., utilize the edible oil capacity measurement testing table that designs voluntarily to detect the dielectric parameter (electric capacity) of the edible oil under the respective conditions.Set up two groups of data dependence equations.The mathematical model of corresponding relation between match edible oil Q factor and the dielectric parameter.

Said signal converter uses Timer T0 and T1, accomplishes regularly 1 second function; The P3.4 pin of single-chip microcomputer is connected to No. 3 output pins of 555 timers, and frequency is carried out accurate counting, and counting error is no more than ± 1HZ; Serially-transmitted data is used in liquid crystal display.

Said alarm is made up of function setting button, 4 LED lights, NPN transistor drive circuit, KC-1206 hummers.The user sets up alarming threshold value and alert if on their own, just reports to the police with the hummer that imposes a condition in case surmount detection threshold, and the testing staff can take the handled measure.

The principle of work of the utility model

Dielectric property and food tissue structure, thermal property, chemical quality etc. are interrelated, through the research to the food dielectric property, can be better qualities such as the composition of food, tissue, state are analyzed and are monitored, and range of application is very extensive.

Test out the dielectric parameter of unknown quality edible oil by capacitance measuring tester, the calculated with mathematical model through match goes out desired values such as corresponding acid value, peroxide value, thereby estimates out the quality of edible oil.Wherein data computing is accomplished by the microcontroller processor, by the LCD liquid crystal display displays.And according to the difference of user to the requirement of edible oil quality; Adjust the alarming threshold value of four edible oil quality index of acquiescence through the function setting button; The corresponding LED light (totally four) of each quality index, the bright number of pilot lamp surpasses setting value x in the testing process.(x ∈ [0,3], x ∈ z), hummer is just reported to the police, and notifies the testing staff to carry out handled.

The physical circuit of capacitance measuring tester is seen accompanying drawing 1.

Accompanying drawing 1 circuit is in resistance R 1; R2 is set under the situation of fixed resistance value; If small variation takes place in capacitor C 1; Obvious variation will take place in the square wave frequency that tests out of 555 counter outputs so, and the change of frequency that reads this square wave through one chip microcomputer just can obtain the size of capacitance, and computing formula is following:

$\left\{\begin{array}{c}{\mathrm{<figure-callout\; id="1"\; label="T"\; filenames="DEST\_PATH\_HSB00000731934800011.png,DEST\_PATH\_HSB00000731934800021.png"\; state="\{\{state\}\}">T</figure-callout>}}_1=(R_1+R_2)\mathrm{<figure-callout\; id="2"\; label="C\; ln"\; filenames="DEST\_PATH\_HSB00000731934800012.png,DEST\_PATH\_HSB00000731934800021.png"\; state="\{\{state\}\}">C</figure-callout>}\ln 2=0.7(R_1+R_2)\mathrm{<figure-callout\; id="2"\; label="C\; T"\; filenames="DEST\_PATH\_HSB00000731934800012.png,DEST\_PATH\_HSB00000731934800021.png"\; state="\{\{state\}\}">C</figure-callout>}& \\ T_{}{}_2=R_2\mathrm{<figure-callout\; id="2"\; label="C\; ln"\; filenames="DEST\_PATH\_HSB00000731934800012.png,DEST\_PATH\_HSB00000731934800021.png"\; state="\{\{state\}\}">C</figure-callout>}\ln 2=0.7R_{2}C\\ T={\mathrm{<figure-callout\; id="1"\; label="T"\; filenames="DEST\_PATH\_HSB00000731934800011.png,DEST\_PATH\_HSB00000731934800021.png"\; state="\{\{state\}\}">T</figure-callout>}}_1+T_2\\ f=\frac{1}{T}\end{array}\right.$

The capacitance parameter of considering edible oil may change less after the heating and cooling of process several times; Above-mentioned capacitance measuring tester can be through regulating the size of resistance R 2; Can test out extremely small capacitance variation (sensitivity can reach the capacitance variations that tests out 2PF), thereby realize accurate measurement edible oil electric capacity.

The beneficial effect of the utility model mainly shows as: 1, volume is little, and is easy to carry; 2, detection speed is fast; 3, accuracy is high; 4, man-machine interface is friendly, and is easy to operate; 5, lack long service life, easy care measuring period.

Description of drawings

Below in conjunction with accompanying drawing and instance the utility model is further specified.

Fig. 1 is the circuit theory diagrams of capacitance measuring tester

Fig. 2 is the instrument outside drawing

Fig. 3 is experimental principle figure

Embodiment

In Fig. 2,8. 7. test contact connect with being connected switch, and 7. test contact is inserted test circuit; 7. test contact is put into the container of edible oil to be measured; And guarantee test contact 7. not with test container wall joint, to avoid causing the out of true of test, carry out above preparation after; Slowly in test container, pour edible oil to be measured into, make edible oil cover test contact 7. 5-10mm be advisable.Press 8. energized of power switch button then, 5. instrument display shows the self check process and welcomes the interface.Press confirming button 2., get into the selection of oils, utilize data to add 1. 3. key carry out oils with the data minus key selection; After confirming, according to detecting required accuracy requirement language function the button setting is set: data add 1. 3. key carry out four quality index ultimate values with the data minus key setting and alarm parameters setting, after setting; Wait for 15s, the microcontroller processor is handled according to data such as temperature that collects and frequencies, 5. shows testing result through display; Corresponding pilot lamp is 6. according to the testing result light on and off; If the bright quantity of pilot lamp surpasses setting value x=[0,3], built-in hummer is reported to the police.When crashing appears in system, during situation such as demonstration mess code, please 4. instrument is resetted by reset key, instrument can normally move once more.

Claims (3)

1. edible oil Quality Detection appearance based on dielectric property; Insulation crust, signal converter, microcontroller processor, display, temperature sensor, alarm lamp, hummer are connected successively; There is capacitive transducer the outside, it is characterized in that: according to the characteristics of circuit, be digital signal with the capacitance simulation conversion of signals of testing in the signal converter---and be the square-wave signal of different frequency; One chip microcomputer is counted the frequency of input; According to different count results, computing draws each parameter of current oil to be measured, send display to show and also selects according to imposing a condition to report to the police.

2. the edible oil Quality Detection appearance based on dielectric property according to claim 1 is characterized by: the test pole plate adopts the stainless steel of 9*9cm, and alternate 1cm is also connected by insulated connectors, and the test pole plate links to each other with 555 circuit of internal circuit; Embedded five buttons on the apparatus subject, control knob, four pilot lamp, a LCD, LCD types is 16*9cm, dark border, blue liquid crystal background.

3. the edible oil Quality Detection appearance based on dielectric property according to claim 1 is characterized by: use Timer T0 and T1, accomplish regularly 1 second function; The P3.4 pin of single-chip microcomputer is connected to No. 3 output pins of 555 timers, and frequency is carried out accurate counting, and counting error is no more than ± 1HZ; Serially-transmitted data is used in liquid crystal display.

Images