CN2094061U

CN2094061U - Comprehensive calibrator for electrical testers

Info

Publication number: CN2094061U
Application number: CN 91217474
Authority: CN
Inventors: 杜仲科; 郭小秦
Original assignee: Individual
Current assignee: Individual
Priority date: 1991-06-26
Filing date: 1991-06-26
Publication date: 1992-01-22

Abstract

The utility model relates to a comprehensive calibrator for electrical testers which can be used as fiber, ordinary pressure as well as temperature calibrator. The comprehensive calibrator for electrical testers comprises a temperature sensor, a force measuring sensor, a function generator, a temperature compensator, a signal amplifier, an A/D converter, a digital display, a power supply, etc. The utility model has the characteristics of high measuring accuracy of the electronic circuit, good temperature characteristic, stable and reliable performance, broad application, strong applicability, small size, light weight, convenient operation, one machine with multifunction, convenient use and cost saving.

Description

Comprehensive calibrator for electrical testers

The utility model relates to the comprehensive calibrator of a kind of examination of fibers with electroprobe, also can do usual pressure, the use of temperature check instrument.

At present, China is in the moisture check of the raw cotton of cotton purchase, handing-over and textile mills, all adopt " the raw cotton moisture teller " of resistance-type, this instrument is the reference instrument of raw cotton water percentage (four tides) check of national Specification, also is the foundation of carrying out quality inspection.Therefore, " raw cotton moisture teller " accurately whether, most important.Make " raw cotton moisture teller " accurate, just must satisfy three conditions technically: the one, to reach 75kg to the pressure of tested cotton; The 2nd, temperature compensation is wanted accurately; The 3rd, it is high that apparent indicating value degree of accuracy is wanted.But for a long time, the apparent indicating value of electroprobe is come verification with resistance box always, and the thermistor that temperature compensation is used is then proofreaied and correct with mercury thermometer.Because mercury thermometer reacts more slowly, smashes easily, troublesome poeration makes suitable unit abandon this school inspection link.In addition, influence the pressure checking of whole test accuracy, so far the method for calibration that does not have science, great majority adopt takes the pressure device apart, press the school with the 75kg counterweight, the trouble that operates more is so school once or not, the general often school of this key technical indexes in the practice is as the criterion with the fixed scale of factory (red point) entirely.Like this, pressure device " red point " after long-term the use moves or spring fatigue, causes pressure inaccurate, tested cotton resistance value is increased or reduce and to draw the moisture mistake of cotton low or too high, lose the accuracy of test, influenced correctly implementing of " excellent cotton favorable rates, the excellent usefulness of excellent cotton " policy.

At above-mentioned problems of the prior art, the purpose of this utility model is to provide a kind of comprehensive calibrator of a tractor serves several purposes of detected pressures, temperature, apparent indicating value simultaneously.This instrument should be intuitively, accurately, conveniently.Its precision should be higher than by the 3--5 of test examination instrument doubly.

Now inventive concept of the present utility model and technical solution are stated as down:

This instrument is by temperature, force cell, function generator, temperature compensator, signal amplifier, A/D converter, compositions such as digital indicator and power supply.The complete machine principle as shown in Figure 1.

The sensor that this instrument adopts is the critical component of instrument, and it directly affects measuring accuracy, and this instrument determines to adopt wheel shaft type compression-type force cell through repeatedly test.Be characterized in that profile is low, precision is high, lateral force resistance is strong, the protection of hermetically sealed inflated with nitrogen, can be in the medium-term and long-term work of the environment of humidity and harmful gas.Because its resistance is subjected to the temperature and pressure variable effect, the utility model has designed temperature-compensation circuit force cell has been carried out rectification building-out in circuit, and linearity circuit is arranged, with the non-linear and temperature drift of erasure signal; The bridge power supply of sensor adopts the high precision integrated regulator, to guarantee the stable of voltage, improves the measuring accuracy of instrument.

The temperature sensor of this instrument adopts accurate platinum resistance, be characterized in the precision height, good stability, but because the temperature-sensitive characteristic of platinum resistance is non-linear, thereby this instrument has adopted the CMOS integrated circuit in the line, the function generator that advanced linearity circuit and cold junction electronic compensation circuit are formed, resistive element is carried out linear compensation, thereby guaranteed between resistance signal and the temperature linear, then by signal amplifier, convert digital signal to through A/D converter and deliver to digital indicator, demonstrate the dut temperature value.

Now that description of drawings is as follows:

Fig. 1: electroprobe overall calibration functional-block diagram

Fig. 2: electroprobe comprehensive calibrator front panel

Fig. 3: electroprobe comprehensive calibrator rear panel

Fig. 4: electroprobe comprehensive calibrator circuit diagram

Wherein: 1, temperature sampler 2, function generator 3, signal amplifier 4, bridge power supply 5, working power 6, dynamometry sampler 7, temperature compensator 9, A/D converter 10, numeral shows 11, resistance box 12, switch 13, corresponding resistance value input 14, resistance box button 15, pressure adjusts 16, display screen 17, switch 18, temperature adjusts 19, selector button 20, temperature verification jack 21, pressure checking jack 22, resistance box jack 23, supply hub

The technical indicator of this instrument is:

1, working environment: environment temperature 0--50 ℃ relative humidity≤80%

2, working power: 220V ± 10% 50HZ

3, measurement range: pressure 0--100ugf(or press customer requirements design)

Temperature 0--199.9 ℃ (or pressing the customer requirements design)

4, measuring accuracy: pressure: ± 0.5%FS

Temperature: ± 0.3%FS

Resistance box: 1 grade (more than 1M Ω) 0.5 grade (1M Ω is following)

5, overload capacity: ± 120--150% FS

This instrument and similar projects technical merit contrast table: (videing infra)

This instrument has the characteristics such as certainty of measurement height, good temp characteristic, linear relationship be good, stable and reliable for performance, this instrument volume is little simultaneously, in light weight, easy to operate, the scope of application is wide, applicability is strong, but a tractor serves several purposes, namely the side makes the user, reduce expenses again, and be desirable pressure, temperature integrated tester.

Claims

1, a kind of electroprobe comprehensive calibrator comprises working power, A/D converter, signal amplifier, digital display circuit, and its characteristics are: this instrument also has temperature sampler, function generator, temperature compensator, resistance box; Direct feed signals amplifier behind the temperature sampling value input function generator; Resistance box behind switch with the resistance value verification mutually of corresponding input.

2, according to a kind of electrometric integrated tester described in the claim 1, it is characterized in that: function generator is made up of CMOS integrated circuit, linearity circuit and cold junction electronic compensation circuit; Be provided with the linear positive electric line of the non-linear and temperature drift of eliminating output signal in the temperature-compensation circuit; The bridge power supply of force cell adopts the high precision integrated regulator.

3, according to the described a kind of electroprobe comprehensive calibrator in the claim 1, it is characterized in that: the temperature sampler adopts platinum sensor; The dynamometry sampler adopts strain-type compression-type sensor.