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绝缘材料体积、表面电阻率测定仪厂家  工作原理

根据欧姆定律，被测电阻R等于施加电压V除以通过的电流I。即

   V

R= ---

   I

传统的仪器的工作原理是测量电压V固定，通过测量流过被测物体的电流I以标定电阻的刻度来读出电阻值。从上式可以看出，由于电流I是与电阻成反比，而不是成正比，所以电阻的显示值是非线性的，即电阻无穷大时，电流为零，即表头的零位处是∞，其附近的刻度非常密，分辨率很低。整个刻度是非线性的。又由于测量不同的电阻时，其电压V也会有些变化，所以普通的高阻计的精度是很难提高的。

BEST-121体积、表面电阻率测定仪是同时测出电阻两端的电压V和流过电阻的电流I，通过内部的大规模集成电路完成电压除以电流的计算，然后把所得到的结果经过A/D转换后以数字显示出电阻值，即便是电阻两端的电压V和流过电阻的电流I是同时变化，其显示的电阻值不象普通高阻计那样因被测电压V的变化或电流Ｉ的变化而变，所以, 即使测量电压、被测量电阻、电源电压等发生变化对其结果影响不大，其测量精度很高。从理论上讲其误差可以做到零。而实际误差可以做到千分之几或万分之几。

绝缘材料体积、表面电阻率测定仪厂家  技术指标

1. 电阻测量范围： 1?104Ω～1?1018Ω，分为十个量程。

2. 电流测量范围为2?10-4A ～1?10-16A

3. 全数字液晶屏显示。

4. 准确度: 准确度优于下表:

( 超出有效显示范围时误差有可能增加)测试电流准确度与电阻相同测试电压准确度为10%

5. 使用环境: 温度 -10℃～50℃ 相对湿度<90%。

6. 测试电压: DC10V、50V、100V、250V、500V、1000V。?10%

7. 供电形式: AC 220V，50HZ，功耗约10W。

8. 仪器尺寸: 300ｍｍ? 280ｍｍ? 150 mm。

9. 质量: 约3.0KG。

典型应用

1 测量防静电鞋、导电鞋的电阻值

按照国家标准GB4386-84《防静电胶底鞋（靴）、导电胶底鞋（靴）电阻值测量方法》防静电鞋的电阻值必须为0.5.?105Ω1.0?108Ω范围内，导电鞋的电阻值必须不大于1.5X105欧姆.不仅制造厂在出厂时必须按这一标准检验，合格后才能出厂，在工厂使用过程中也必须按这一标准进行定期检验，合格后才能穿用。

制造厂测量新鞋的电阻值时，应将硫化后有新鞋放置24小时以上，然后在测量所要求的温度、湿度环境中放置2小时以后才能进行测量。使用单位在定期检测时应将鞋洗干净，其温湿度的要求及放置时间同上。测量环境要求为：温度：10℃ ～ 40℃相对湿度为40% ～ 70%。 由于HEST121型数字表面、体积电阻率测定仪是内部同时测量电压和电流，且直接显示出电阻值，所以不必另外使用电压表和电流表以及计算电阻值。

通常测试防静电鞋只用106、107、108Ω档，测试完毕将开关拨回104档。

根据上述测试的结果，根据标准来确定被测鞋是否合格或能否穿用。

2. 测量防静电材料的电阻及电阻率

一般防静电材料的电阻值在105 Ω～1010 Ω左右的范围内，其测量电极可采用三电极或二电极，其具体测量方法可参照有关的标准或有关资料。

3. 测量计算机房用活动地板的系统电阻值

按照国家标准ＧＢ6650-86《计算机房用活动地板技术条件》。采用该标准的电极（也可用三电极中的主电极）测量。

4. 测量绝缘材料电阻(率)

绝缘材料如塑料（聚乙稀，聚氯乙稀，尼龙等）橡胶等的电阻率很高，测量时应采取屏蔽措施，以免读数不稳甚至无法测量。测量时可采用三电极。具体方法可参照国家标准GB1410。

5. 测量电流及1014Ω以上超高电阻的测量

当测量超过1014Ω以上的超高电阻时,可以通过测量电流的方法,然后用欧姆

定律求出超高电阻值。测量电流与测量电阻的方法基本相同，

例如：电流表头显示读数为1.234，量程位置处在10－8，则电流为I=1.234?10-8 A

利用欧姆定律

V

R= ---

I

可以计算出电阻值。利用测量电流的方法可测量超过1014Ω以上的超高电阻1015～1018Ω。 

主要标准：

GB/T 1410-2006 《 固体绝缘材料体积电阻率和表面电阻率试验方法》

ASTM D257-99  《绝缘材料的直流电阻或电导试验方法》

GB/T 2439-2001《硫化橡胶或热塑性橡胶 导电性能和耗散性能电阻率的测定》

GB/T 10581-2006 《绝缘材料在高温下电阻和电阻率的试验方法》

GB/T 1692-2008 《硫化橡胶绝缘电阻率的测定》

GB/T 12703.4-2010 《纺织品 静电性能的评定 第４部分：电阻率》

GB/T 10064-2006《测定固体绝缘材料绝缘电阻的试验方法》

标准配置：

1,测试仪器：1台

2,电源线：1条

3,测量线：3根（屏蔽线,测试接线,接地线）

4,使用说明书：1份

working principle

According to Ohm's Law, the measured resistance R is equal to the applied voltage V divided by the current I passing through. That is

V

R= ---

I

The working principle of traditional instruments is to measure a fixed voltage V and read the resistance value by measuring the current I flowing through the measured object to calibrate the resistance scale. From the above equation, it can be seen that since the current I is inversely proportional to the resistance, rather than directly proportional, the displayed value of the resistance is nonlinear. That is, when the resistance is infinite, the current is zero, and the zero position of the meter head is ∞. The scales near it are very dense, and the resolution is very low. The entire scale is non-linear. Moreover, due to the variation in voltage V when measuring different resistances, it is difficult to improve the accuracy of ordinary high resistance meters.

The BEST-121 volume and surface resistivity measuring instrument simultaneously measures the voltage V across the resistor and the current I flowing through the resistor. The voltage divided by the current is calculated through an internal large-scale integrated circuit, and the obtained result is then converted into a digital display of the resistance value through A/D conversion. Even if the voltage V across the resistor and the current I flowing through the resistor change simultaneously, the displayed resistance value does not change due to changes in the measured voltage V or current I like ordinary high resistance meters. Therefore, even if there are changes in the measured voltage, measured resistance, power supply voltage, etc., the measurement accuracy is very high. In theory, its error can be reduced to zero. And the actual error can reach a few thousandths or tens of thousands.

Technical indicators

1. Resistance measurement range: 1 ? 104 Ω~1 ? 1018 Ω, divided into ten measuring ranges.

2. The current measurement range is 2 ? 10-4A to 1 ? 10-16A

3. Full digital LCD screen display.

4. Accuracy: The accuracy is better than the following table:

Effective display range of range: 20-30 ℃ RH<80%

104 0.01~19.99 1%

105 0.01～19.99 1%

106 0.01～19.99 1%

107 0.01～19.99 1%

108 0.01～19.99 1%

109 0.01～19.99 1%

1010 0.01~19.99 5% 2 words

1011 0.01~19.99 5% 2 words

1012 0.01~19.99 5% 5 words

1013 0.01~19.99 10% 5 words

1014 0.01~19.99 10% 5 words

Above 1014, 0.01~19.99, 10-15% 5 words

The accuracy of the test current is the same as that of the resistance, and the accuracy of the test voltage is 10%

5. Operating environment: Temperature -10 ℃~50 ℃, relative humidity<90%.

6. Test voltage: DC10V、50V、100V、250V、500V、1000V。 ?10%

7. Power supply form: AC 220V，50HZ， The power consumption is about 10W.

8. Instrument size: 300mm ? 280mm ? 150mm.

9. Quality: Approximately 3.0KG.

Typical applications

Measure the resistance value of anti-static shoes and conductive shoes

According to the national standard GB4386-84 "Measurement method for resistance value of anti-static rubber soled shoes (boots) and conductive rubber soled shoes (boots)", the resistance value of anti-static shoes must be within the range of 0.5. ? 105 Ω 1.0 ? 108 Ω, and the resistance value of conductive shoes must not exceed 1.5X105 Ω Not only must the manufacturing plant be inspected according to this standard before leaving the factory, but it must also be regularly inspected according to this standard during use in the factory, and only after passing the inspection can it be worn.

When measuring the resistance value of new shoes in the manufacturing plant, the vulcanized new shoes should be left for more than 24 hours, and then placed in the required temperature and humidity environment for 2 hours before measurement can be carried out. The user unit should wash the shoes clean during regular inspections, with the same temperature and humidity requirements and storage time as above. The measurement environment requirements are: temperature: 10 ℃~40 ℃, relative humidity: 40%~70%. Due to the HEST121 digital surface and volume resistivity meter measuring both voltage and current internally and displaying resistance values directly, there is no need to use separate voltmeters and ammeters to calculate resistance values.

Usually, anti-static shoes are tested using only 106, 107, and 108 Ω settings. After testing, turn the switch back to 104.

Based on the results of the above tests, determine whether the tested shoes are qualified or can be worn according to the standards.

2. Measure the resistance and resistivity of anti-static materials

The resistance value of general anti-static materials is in the range of around 105 Ω to 1010 Ω, and their measuring electrodes can use three or two electrodes. The specific measurement method can refer to relevant standards or data.

3. Measure the system resistance value of the raised floor used in the computer room

According to the national standard GB6650-86 "Technical Conditions for Raised Floor in Computer Room". Measure using the electrode of this standard (or the main electrode among the three electrodes).

4. Measure the resistance (rate) of insulation materials

Insulating materials such as plastics (polyethylene, polyvinyl chloride, nylon, etc.) and rubber have high electrical resistivity, and shielding measures should be taken during measurement to avoid unstable readings or even inability to measure. Three electrodes can be used for measurement. The specific method can refer to the national standard GB1410.

5. Measurement of current and ultra-high resistance above 1014 Ω

When measuring ultra-high resistance exceeding 1014 Ω, the method of measuring current can be used, and then ohms can be used

The law determines the ultra-high resistance value. The methods for measuring current and measuring resistance are basically the same,

For example, if the ammeter displays a reading of 1.234 and the range is between 10-8, then the current is I=1.234 ? 10-8 A

Using Ohm's Law

V

R= ---

I

The resistance value can be calculated. The method of measuring current can be used to measure ultra-high resistance of 1015-1018 Ω exceeding 1014 Ω.

Main standards:

GB/T 1410-2006 "Test Method for Volume and Surface resistivity of Solid Insulation Materials"

ASTM D257-99 "Test Method for DC Resistance or Conductivity of Insulation Materials"

GB/T 2439-2001 "Determination of Electrical Conductivity and Dissipation Properties of Vulcanized Rubber or Thermoplastic Rubber"

GB/T 10581-2006 "Test method for resistance and resistivity of insulating materials at high temperatures"

GB/T 1692-2008 "Determination of Insulation Resistance of Vulcanized Rubber"

GB/T 12703.4-2010 "Evaluation of electrostatic properties of textiles - Part 4: Electrical resistivity"

GB/T 10064-2006 "Test Method for Determining Insulation Resistance of Solid Insulation Materials"

Standard configuration:

1. Testing instrument: 1 unit

2. Power cord: 1

3. Measurement wires: 3 wires (shielded wire, test wire, grounding wire)

4. User manual: 1 copy

温度影响

温度对不同物质的电阻值均有不同的影晌。

导电体在接近室温的温度，良导体的电阻值，通常与温度成线性关系：

ρ=ρ0(1 αt)

上式中的a 称为电阻的温度系数。

未经掺杂的半导体的电阻随温度升高而下降：

有掺杂的半导体变化较为复杂。当温度从绝对零度上升，半导体的电阻先是减少，到了绝大部分的带电粒子（电子或电洞/空穴） 离开了它们的载体后，电阻会因带电粒子的活动力下降而随温度稍为上升。当温度升得更高，半导体会产生新的载体 （和未经掺杂的半导体一样） ，原有的载体 （因渗杂而产生者） 重要性下降，于是电阻会再度下降。

绝缘体和电解质绝缘体和电解质的电阻与温度的关系一般不成比例，而且不同物质有不同的变化，故不在此列出概括性的算式。

电源

要求有很稳定的直流电压源。这可用蓄电油或一个整流稳压的电摞来提供。对电源的稳定度要求是由电压变化导致的电流变化与被测电流相比可忽略不计。

加到整个试样上的试验电压通常规定为100V、250V、500V、1000 V、2500 V、5000 V, 10000 V 和15000 V。 常用的电压是100V、500V和1000 V。

在某些情况下，试样的电阻与施加电压的极性有关

如果电阻是与极性有关的，则宜加以注明。取两次电阻值的几何平均值（对数算术平均值的反对数）作为结果。

由于试样电阻可能与电压有依存关系，因此应在报告中注明试验电压值。

报告

报告应至少包括下述情况：

a) 电阻率测试仪（电阻率测定仪）关于材料的说明和标志（名称、等级、颜色、制造商等）；

b) 电阻率测试仪（电阻率测定仪）试样的形状和尺寸；

c) 电阻率测试仪（电阻率测定仪）电极和保护装置的形式、材料和尺寸；

d) 电阻率测试仪（电阻率测定仪）试样的处理（清洁、预干燥、处理时间、湿度和温度）等；

e) 电阻率测试仪（电阻率测定仪）试验条件（试样温度、相对由度）；

f) 电阻率测试仪（电阻率测定仪）测量方法；

g) 电阻率测试仪（电阻率测定仪）施加电压；

h) 电阻率测试仪（电阻率测定仪）体和、电阻率（需要时）；

注1：当规定了一个固定的电化时间时，注明此时间，给出个别值，并报告中值作为体积电阻率。

注2 ： 当在不同的电化时间后测试时，应按如下要求报告：

当在相同的电化时间里试样达到一个稳定状态肘，给出个别值，并报告中值作为体积电阻率。在这个电化时间里有某些试样不能达到稳定状态，则报告不能达到稳定状态的试样数，并分别地给出它们的结果。当测试结果取决于电化时间时，则报告它们之间的关系，例如．以图的形式或给出在电化Imin、10min和100min后的体积电阻率的中值。

i) 表面电阻率（需要时）：

给出电化时间为1 min的个别值，并报告其中值作为表面电阻率。