型號：BEST-121

一、體積電阻率表面電阻率測試儀特點

 本儀器既可測量超高電阻,又可測極微弱電流。采用了大規模集成電路以及的技 術，使儀器體積小、重量輕、準確度高。以數字液晶顯示電阻并同時 直接顯示流過被測電阻的電流。電阻量限從1×104Ω～1×1018Ω， 電流測量范圍 為2×10-4A～1×10-16A。機內測試電壓為DC10V、50V、100V、250V、500V、1000V。本儀器具有精度高、顯示迅速、性好穩定、讀數方便, 適用于防靜電產品如防靜電鞋、防靜電塑料橡膠制品、計算機房防靜電活動地板等電阻值的檢驗以及絕緣材料和電子電器產品的絕緣電阻測量。本儀器除能測電阻外，還能直接測量電流如電子器件暗電流等。

二、體積電阻率表面電阻率測試儀測量指標 

1  電阻測量范圍 1×104Ω～1×1018Ω； 

2  電流測量范圍 2×10-4Ａ～1×10-16Ａ； 

3 體積小、重量輕、準確度高；

4  *的被測電阻、和流過電阻的電流雙顯示，使操作測量更加方便；

5  性能穩定、讀數方便；

6  既能測電阻又能測電流；

7  測試電壓有六種選擇之多DC10V、50V、100V、250V、500V、1000V；

8  使用操作簡便，在任何電阻量程和測試電壓下均直接讀顯示數字結果，

免去要乘以一個系數的麻煩，使測量超高電阻就如用萬用表測量普通電阻樣簡便。

三、適用的主要標準：

GB/T 1410-2006 固體絕緣材料 體積電阻率和表面電阻率試驗方法

GB 12014 防靜電工作服

GB/T 20991-2007 個體防護裝備 鞋的測試方法

GB 4385-1995 防靜電鞋、導電鞋技術要求 

GB 12158-2006 防止靜電事故通用導則

GB 4655-2003 橡膠工業靜電安全規程

GB/T 12703.4-2010 紡織品 靜電性能的評定 第4部分 電阻率

GB/T 12703.6-2010 紡織品 靜電性能的評定 第6部分 纖維泄漏電阻

GB 13348-2009 液體石油產品靜電安全規程

GB/T 15738-2008 導電和抗靜電纖維增強塑料電阻率試驗方法

GB/T 18044-2008 地毯 靜電習性評價法 行走試驗

GB/T 18864-2002 硫化橡膠 工業用抗靜電和導電產品 電阻極限范圍

GB/T 22042-2008 服裝 防靜電性能 表面電阻率試驗方法

GB/T 22043-2008 服裝 防靜電性能 通過材料的電阻（垂直電阻）試驗方法

GB/T 24249-2009 防靜電潔凈織物

GB 26539-2011 防靜電陶瓷磚 Antistatic ceramic tiles

GB/T 26825-2011 抗靜電防腐膠

GB 50515-2010 導（防）靜電地面設計規范

GB 50611-2010 電子工程防靜電設計規范

GJB 105-1998-Z 電子產品防靜電放電控制手冊

GJB 3007A-2009 防靜電工作區技術要求

GJB 5104-2004 無線電引信風帽用防靜電涂料及風帽靜電性能通用要求

四、體積電阻率表面電阻率測試儀技術指標

1.   電阻測量范圍： 1×104Ω ～1×1018Ω，分為十個量程。

2.   電流測量范圍為2×10-4A ～1×10-16A

3.  全數字液晶屏顯示。

4.  準確度: 準確度優于下表:

量程有效顯示范圍20～30℃ RH<80%

1040.01~19.991%

1050.01～19.991%

1060.01～19.991%

1070.01～19.991%

1080.01～19.991%

1090.01～19.991%

10100.01～19.995%+2字

10110.01～19.995%+2字

10120.01～19.995%+5字

10130.01～19.9910%+5字

10140.01～19.9910%+5字

1014以上0.01～19.9910-15%+5字

（ 超出有效顯示范圍時誤差有可能增加）

測試電流準確度與電阻相同）

測試電壓準確度為 10%

5. 使用環境: 溫度 -10℃～50℃相對濕度<90%。

6. 測試電壓:DC10V、50V、100V、250V、500V、1000V。±10%

7. 供電形式: AC 220V，50HZ，功耗約10W。

8. 儀器尺寸: 300ｍｍ× 280ｍｍ× 150 mm。

9. 質量: 約3.0KG。

五、名詞術語 

1） 絕緣電阻：施加在與試樣相接觸的二電極之間的直流電壓除以通過兩電極的總電流所得的商。它取決于體積電阻和表面電阻。

2） 體積電阻：在試樣的相對兩表面上放置的兩電極間所加直流電壓與流過兩個電極之間的穩態電流之商；該電流不包括沿材料表面的電流。在兩電極間可能形成的極化忽略不計。

3） 體積電阻率：絕緣材料里面的直流電場強度與穩態電流密度之商，即單位體積內的體積電阻。

4） 表面電阻：在試樣的某一表面上兩電極間所加電壓與經過一定時間后流過兩電極間的電流之商；該電流主要為流過試樣表層的電流，也包括一部分流過試樣體積的電流成分。在兩電極間可能形成的極化忽略不計。

5）表面電阻率：在絕緣材料的表面層的直流電場強度與線電流密度之商，即單位面積內的表面電阻。

六、測量技術 

a.通常，絕緣材料用于電氣系統的各部件相互絕緣和對地絕緣，固體絕緣材料還起機械支撐作用。一般希望材料有盡可能高的絕緣電阻，并具有合適的機械、化學和耐熱性能。

b.絕緣材料的電阻率一般都很高，也就是傳導電流很小。如果不注意外界因素的干擾和漏電流的影響，測量結果就會發生很大的誤差。同時絕緣材料本身的吸濕性和環境條件的變化對測量結果也有很大影響。

c.影響體積電阻率和表面電阻率測試的主要因素是溫度和濕度、電場強度、充電時間及殘余電荷等。體積電阻率可作為選擇絕緣材料的一個參數，電阻率隨溫度和濕度的變化而顯著變化。體積電阻率的測量常常用來檢查絕緣材料是否均勻，或者用來檢測那些能影響材料質量而又不能用其他方法檢測到的導電雜質。

d.由于體積電阻總是要被或多或少地包括到表面電阻的測試中去，因此只能近似地測量表面電阻，測得的表面電阻值主要反映被測試樣表面污染的程度。所以，表面電阻率不是表征材料本身特性的參數，而是一個有關材料表面污染特性的參數。當表面電阻較高時，它常隨時間以不規則的方式變化。測量表面電阻通常都規定1min的電化時間。 

（1）溫度和濕度：固體絕緣材料的絕緣電阻率隨溫度和濕度的升高而降低，特別是體積電阻率隨溫度改變而變化非常大。因此，電瓷材料不但要測定常溫下的體積電阻率，而且還要測定高溫下的體積電阻率，以評定其絕緣性能的好壞。由于水的電導大，隨著濕度增大，表面電阻率和有開口孔隙的電瓷材料的體積電阻率急劇下降。因此，測定時應嚴格地按照規定的試樣處理要求和測試的環境條件下進行。

（2）電場強度：當電場強度比較高時，離子的遷移率隨電場強度增高而增大，而且在接近擊穿時還會出現大量的電子遷移，這時體積電阻率大大地降低。因此在測定時，施加的電壓應不超過規定的值。

（3）殘余電荷：試樣在加工和測試等過程中，可能產生靜電，電阻越高越容易產生靜電，影響測量的準確性。因此，在測量時，試樣要*放電，即可將幾個電極連在一起進行短路。

（4）雜散電勢的消除：在絕緣電阻測量電路中，可能存在某些雜散電勢，如熱電勢、電解電勢、接觸電勢等，其中影響zui大的為電解電勢。用高阻計測量表面潮濕的試樣的體積電阻時，測量極與保護極間可產生20mv的電勢。試驗前應檢查有無雜散電勢?？筛鶕嚇蛹訅呵昂蟾咦栌嫷亩沃甘臼欠裣嗤瑏砼袛嘤袩o雜散電勢。如相同，證明無雜散電勢；否則應當尋找并排除產生雜散電勢的根源，才能進行測量。

（5）防止漏電流的影響：對于高電阻材料，只有采取保護技術才能去除漏電流對測量的影響。保護技術就是在引起測量誤差的漏電路徑上安置保護導體，截住可能引起測量誤差的雜散電流，使之不流經測量回路或儀表。保護導體連接在一起構成保護端，通常保護端接地。測量體積電阻時，三電極系統的保護極就是保護導體。此時要求保護電極和測量電極間的試樣表面電阻高于與它并聯元件的電阻10～100倍。線路接好后，應首先檢查是否存在漏電。此時斷開與試樣連接的高壓線，加上電壓。如在測量靈敏度范圍內，測量儀器指示的電阻值為無限大，則線路無漏電，可進行測量。

（6）條件處理和測試條件的規定:固體絕緣材料的電阻隨溫度、濕度的增加而下降。試樣的預處理條件取決于被測材料，這些條件在材料規范中規定。推薦使用GB10580《固體絕緣材料在試驗前和試驗時采用的標準條件》中規定的預處理方法?？墒褂酶视?mdash;水溶液潮濕箱進行濕度預處理。測試條件應與預處理條件盡可能地*，有些時候（如浸水處理）不能保持預處理條件和測試條件*時，則應在從預處理環境中取出后在盡可能短時間內完成測試，一般不超過5分鐘。

（7）電化時間的規定:當直流電壓加到與試樣接觸的兩電極間時，通過試樣的電流會指數式地衰減到一個穩定值。電流隨時間的減小可能是由于電介質極化和可動離子位移到電極所致。對于體積電阻率小于1010Ω·m的材料，其穩定狀態通常在1分鐘內達到。因此，要經過這個電化時間后測定電阻。對于電阻率較高的材料，電流減小的過程可能會持續幾分鐘、幾小時、幾天，因此需要用較長的電化時間。如果需要的話，可用體積電阻率與時間的關系來描述材料的特性。當表面電阻較高時，它常隨時間以不規則的方式變化。測量表面電阻通常都規定1分鐘的電化時間

。

七、體積電阻率表面電阻率測試儀使用注意事項： 

 高阻測量一定要嚴格按使用方法步聚進行，否則有可能造成儀器*損壞或電人。  

１、 應在“Ｒｘ”兩端開路時調零  如接在電阻箱或被測量物體上時調零后測量會產生很大的誤差。一般一次調零后在測試過程中不需再調零，但改變測量電壓后可能要重新調零。  

２、 禁止將“Ｒｘ”兩端短路，以免微電流放大器受大電流沖擊  

３、 在測試過程中不要隨意改動測量電壓，  隨意改動測量電壓可能因電壓的過高或電流過大損壞被測試器件或測試儀器，而且有的材料是非線性的，即電壓與電流是不符合歐姆定律，有改變電壓時由于電流不是線性變化，所以測量的電阻也會變化。 

４、 測量時從低次檔逐漸拔往高次檔  每撥一次稍停留1～2秒以便觀察顯示數字，當有顯示值時應停下，記錄當前的數字即是被測電阻值。若顯示“1”時，表示欠量程應往高次檔拔。直到有顯示數字時為止。當有顯示數字時不能再往高次檔撥，否則有可能損壞儀器（機內有過電流保護電路）。除104 Ω檔之外，當顯示低于1.99，表示過量程應換低檔! 

５、 大部分絕緣材料，特別是防靜電材料的電阻值在加電壓后會有一定變化而引起數字變化  由于本儀器的分辯率很高，因而會引起顯示值的末尾幾位數也變化，這不是儀器本身的問題，而是被測量對象的導電機理復雜而使得阻值有些變化。在這種情況下往往取2位有效數就夠了。  

６ 、接通電源后，手指不能觸及高壓線的金屬部分  本儀表有二連根線：高壓線（紅）和微電流測試線。在使用時要注意高壓線，開機后人不能觸及高壓線，以免電人或麻手。 

７ 、測試過程中不能觸摸微電流測試端  微電流測試端zui怕受到大電流或人體感應電壓及靜電的沖擊。所以在開機后和測試過程中不能與微電流測試端接觸，以免損壞儀表。  

８、 在測量高阻時，應采用屏蔽盒將被測物體屏蔽．  在測量大于1010 Ω以上時，為防止外界干擾面而引起讀數不穩。 

９、 每次測量完時應將量程開關撥回“１０４ ”檔再進行下次測試  在測量時應逐漸將量程開關撥到高阻檔，測量完時應將量程開關撥回低檔。以確保下次開機時量程開關處在低阻量程檔。

人體一般可以帶上幾千甚至幾萬伏靜電！

八、高阻測量常見問題

1 。為什么在測量同一物體時用不同的電阻量程有不同的讀 數？

這是因為測量電阻時為防止過電壓損壞儀器，如果出現過量程時儀器內保護電路 開始工作，將測試電壓降下來以保護機內放大器。在不同的電壓下測量同一物體會 有不同的結果。而且當測量電阻時若讀數小于199，既只為三位數且*位數為1 時，其準確度要下降。所以在測量電阻時當*次讀數從1 變為某一讀數時，不應 再往更高的量程扭開關以防對儀器造成過大的電流沖擊。在實際使用時，即讀數位 數多的比讀數位數少的準確度高。

2 ．為什么測量一些物體的電流時用不同的量程也會出現測出結 果相差較大？

這是因為一般物體輸出的電流不是恒定流，而儀器有一定內阻，若在儀器上所選 量程的內阻過大以至于在儀器上的電壓降影響被測物體的輸出電流時會造成測量誤差。一般電流越小的量程內阻越高，所以在測量電流時應選用電流大的量程。在實 際使用時即只要電流表有讀數時，讀數位數少的小的比讀數位數多的準確度高。

3．為什么測量時儀器的讀數總是不穩？

一般的材料其導電性不是嚴格像標準電阻樣在一定的電壓下有很穩定的電流，有 很多材料特別是防靜電材料其導電性不符合歐姆定律，所以在測量時其讀數不穩。 這不是儀器的問題，而是被測量物體的性能決定的。有的標準規定以測量1分鐘時間 的讀數為準。通常在測量高電阻或微電流時測量準確度因重復性不好，對測量讀數 只要求2位或3位。另外在測量大電阻時如果屏蔽不好也會因外界的電磁信號對儀器 測量結果造成讀數不穩。

4.   這是因為在測量時被測物體及儀器輸入端都有一定的電容，這個電容在測量時已 被充電到測量電阻時的電壓值，如果儀器不撥到104擋后關電源這個充電后的電容器 會對儀器內的放大器放電而造成儀器損壞。當被測量物體電容越大，測試電壓越高 時，電容器所儲藏的電能越大，更容易損壞儀器，特別是在電阻的高量程或電流的 低量程時因儀器非常靈敏，儀器過載而損壞的可能性更大。所以一定要將量程開關 再撥到104擋后才能關電源。

5。 為什么在測量電阻過程中不要改變對被測物的測試電 壓？

在測量電阻過程中如果改變對被測物的測試電壓，無論電壓變高或變低時都將 會產生大脈沖電流，這個大的電流很有可能使儀器過量程甚至更損壞儀器。另一方 面如果電壓突然變化也會通過被測量物體的（分布）電容放電或反向放電對測量儀 器造成沖擊而損壞儀器。有的物體的耐壓較低，當您改變測量電壓時有右能擊穿而 產生大電流損壞儀器。如果要改變測量電壓，在確保被測量物體不會因電壓過高擊 穿時，要先將量程開關撥到104檔后關閉電源，再從儀器后面板調整到所要求的電 壓。有的材料是非線性的，即電壓與電流是不符合歐姆定律，有改變電壓時由于電流不是線性變化，所以測量的電阻也會變化。

6 。為什么測量完畢要將量程開關再撥到 104 檔后關閉電源？

這是因為機內的電容器充有很高的電壓（zui高電壓達1200V以上），這些電容器的 所帶的電能保持較長的時間，如果關閉電源開關，則會將機內的高壓電容器很快放 電，不會在測量的高壓端留有很危險的電壓造成電擊。如果僅撥電源線而不是關電 源開頭，雖然斷了電源，但機內高壓電容器還有會因長時間保持很高的電壓，將會 對人員或其它物體造成電擊或損壞。在儀器有問題時也不要隨便打開機箱因機內高壓造成電擊，要將儀器找專業技術人員或寄回廠家修理。

九、體積電阻率表面電阻率測試儀主要應用范圍 

a    材料高阻測試測量如防靜電產品（防靜電鞋、防靜電塑料橡膠制品、計 算機房防靜電活動地板等）電阻值的檢測；

b    材料體積電阻（率）和表面電阻（率）測量；

c    電化學和材料測試,以及物理,光學和材料研究;

d    微弱電流測量如光電效應和器件暗電流測量。

附加介紹：

電阻率

電阻率是用來表示各種物質電阻特性的物理量。某種材料制成的長1米、橫截面積是1平方毫米的在常溫下（20℃時）導線的電阻，叫做這種材料的電阻率。電阻率的單位是歐姆·米（Ω·m或ohmm），常用單位是歐姆·毫米和歐姆·米。

應用

電阻率較低的物質被稱為導體，常見導體主要為金屬，而自然界中導電性*的是銀，其次為半導體，、硅鍺。當存在外電場時，金屬的自由電子在運動中不斷和晶格節點上做熱振子的正離子相碰撞，使電子運動受到阻礙，因而就具有了一定的電阻。其他不易導電的物質如玻璃、橡膠等，電阻率較高，一般稱為絕緣體。介于導體和絕緣體之間的物質（如硅） 則稱半導體。電阻率的科學符號為 ρ（Rho）。 已知物體的電阻，可由電阻率ρ、長度 l 與截面面積A 計算：ρ=RA/I，在該式中， 電阻R 單位為歐姆，長度 l 單位為米，截面面積 A 單位為平方米，電阻率 ρ單位為

歐姆·米

計算公式

電阻率的計算公式為：ρ=RS/L

ρ為電阻率——常用單位Ω·m

S為橫截面積——常用單位㎡

R為電阻值——常用單位Ω

L為導線的長度——常用單位m

-----------------------------------------

電阻率的另一計算公式為：ρ=E/J

ρ為電阻率——常用單位Ω·mm2/m[1]

E為電場強度——常用單位N/C

J為電流密度——常用單位A/㎡

（E，J 可以為矢量）

說明

1．電阻率ρ不僅和導體的材料有關，還和導體的溫度有關。在溫度變化不大的范圍內：幾乎所有金屬的電阻率隨溫度作線性變化，即ρ=ρo（1+at）。式中t是攝氏溫度，ρo是O℃時的電阻率，a是電阻率溫度系數。

2．由于電阻率隨溫度改變而改變，所以對于某些電器的電阻，必須說明它們所處的物理狀態。如一個220 V -100 W電燈燈絲的電阻，通電時是484歐姆，未通電時只有40歐姆左右。

3．電阻率和電阻是兩個不同的概念。電阻率是反映物質對電流阻礙作用的屬性，電阻是反映物體對電流阻礙作用的屬性。

總結：

常態下（由表可知）導電性能的依次是銀、銅、鋁，這三種材料是zui常用的，常被用來作為導線等，其中銅用的zui為廣，幾乎現在的導線都是銅的（精密儀器，特殊場合除外）鋁線由于化學性質不穩定容易氧化已被淘汰。由于鋁密度小，取材廣泛，且價格比銅便宜，目前被廣泛用于電力系統中傳輸電力的架空輸電線路。為解決鋁材剛性不足缺陷，一般采用鋼芯鋁絞線，即鋁絞線內部包有一根鋼線，以提高強度。銀導電性能，但由于成本高很少被采用，只有在高要求場合才被使用，如精密儀器、高頻震蕩器、航天等。順便說下金，在某些場合儀器上觸點也有用金的，那是因為金的化學性質穩定故采用，并不是因為其電阻率小所致。

北京北廣精儀儀器設備有限公司熱銷產品：

（橡膠塑料電性能系列）電壓擊穿試驗儀，電氣強度測試儀，介電擊穿強度測定儀，電子萬能試驗機，體積電阻率表面電阻率測試儀，介電常數及介質損耗測試儀，漏電起痕試驗儀，水平垂直燃燒儀，橡膠低溫脆性沖擊試驗儀，熔融指數儀，熔體流動速率測定儀，塑料熱變形維卡軟化點溫度測定儀，滑動摩擦磨損試驗機，耐電弧試驗機，馬丁耐熱試驗儀，建材可燃試驗儀，球壓痕硬度計，簡支梁試驗機，電熱毯動負載試驗機，萬能試驗機，沖片機，啞鈴制樣機，落錘沖擊、落鏢沖擊，落球沖擊試驗機，指數儀等

（海綿泡沫系列）海綿泡沫壓陷硬度測定儀，落球回彈試驗機，海綿切割機，海綿拉伸強度試驗機，和疲勞壓陷試驗機，壓縮變形試驗機，撕裂強度，回彈率等。

售后服務及保修承諾：

多年來，我公司一直專業生產研究電氣試驗設備，經研究、摸索、總結出一套完整的產品服務保障體系，向用戶提供優質及時的售前、售中、售后服務

為創造，提高企業度，樹立企業形象，我們本著“一切追求高質量，用戶滿意為宗旨”的精神，以“*惠的價格、zui周到的服務、zui可靠的產品質量”的原則向您鄭重承諾：

一、產品質量承諾：

1、我公司保證向需方提供的設備是原廠生產的，并且出廠資料配件齊全。為保持合同設備的正常運行和維護，我公司保證提供的技術資料和圖紙是完整、清楚和正確的。

2、產品的制造和檢測均有質量記錄和檢測資料。

3、對產品性能的檢測，我們誠請用戶親臨對產品進行全過程、全性能檢查，待產品被確認合格后再裝箱發貨。

二、產品價格承諾：

1、為了保證產品的高可靠性和先進性，系統的選材均選用國內或優質產品。

2、在同等競爭條件下，我公司在不以降低產品技術性能、更改產品部件為代價的基礎上，真誠以*惠的價格提供給貴方。

三：安裝調試及驗收承諾：

1、協助設備的安裝，負責設備的運輸、調試。

2、設備按訂貨技術附件進行驗收。終驗收在買方進行，對用戶提供的試樣進行試驗，并提供測試報告。

3、安裝調試同時，在儀器操作現場一次性免費培訓操作人員2-3名，該操作人員應是由需方選派的長期穩定的員工，培訓后能夠對設備基本原理、軟件使用、操作、維護事項理解和應用，使人員能夠獨立操作設備對樣品進行檢測、分析，同時能進行基本的維護。 

四、保修承諾：

1、設備保修一年，終身服務，一年內非人為損壞的零部件免費更換，保修期內接到用戶邀請后， zui遲響應時間為2小時內，在與用戶確認故障后，我公司會在48小時內派工程師到達現場進行

免費服務，盡快查清故障所在位置和故障原因，并向用戶及時報告故障的原因和排除辦法 。

2、保修期內人為損壞的零部件按采購（加工）價格收費更換。

3、保修期外繼續為用戶提供優質技術服務，在接到用戶維修邀請后3天內派工程師到達用戶現場進行維修。并享有優惠購買零配件的待遇?！?/p>

4、傳感器過載及整機電路超壓損壞不在保修范圍內。

Factory direct sales volume resistivity Surface resistivity tester （three electrode method）

Model: BEST-121

First, the volume resistivity Surface resistivity tester Features

 The instrument can measure high resistance, can be measured very weak currents. Using the LSI and the latest patented technology, equipment, small size, light weight, high accuracy. Digital LCD display resistance while direct current flowing through the measured resistance.

Resistance limit from 1 × 104Ω ~ 1 × 1018Ω, the current measuring range of 2 × 10-4A ~ 1 × 10-16A. In test voltage is DC10V, 50V, 100V, 250V, 500V, 1000V. This instrument has high precision, showing rapid, good stability, reading

Convenient for static, such as anti-static shoes, anti-static plastics and rubber products, anti-static raised floor computer room and other resistance testing and insulation materials and electrical and electronic products, insulation resistance measurement. In addition to the instrument can measure resistance, but also can directly measure the electrical

Streams such as electronic devices dark current.

Second, the volume resistivity Surface resistivity tester measure

A resistance measurement range of 1 × 104Ω ~ 1 × 1018Ω;

2 current measurement range 2 × 10-4A ~ 1 × 10-16A;

3, small size, light weight, high accuracy;

4 unique measured resistance, and the current flowing through the resistor dual display makes the operation more convenient measurement;

5 stable performance, easy reading;

6 can measure both current sensing resistor;

7 There are six options as much as test voltage DC10V, 50V, 100V, 250V, 500V, 1000V;

8 Use the easy to operate, at any resistance range and test voltages are read directly show numerical results

Eliminates the trouble to be multiplied by a coefficient, high resistance of the measurement as measured with a multimeter ordinary electric

Resistance like simple.

Third, the main criteria for:

GB / T 1410-2006 volume resistivity of insulating materials and surface resistivity test methods

GB 12014 Antistatic overalls

GB / T 20991-2007 Personal protective equipment - Test methods for footwear

GB 4385-1995 anti-static shoes, conductive shoes technical requirements

GB 12158-2006 General Guidelines for preventing electrostatic accidents

GB 4655-2003 Safety regulations for electrostatic rubber industry

GB / T 12703.4-2010 Textiles electrostatic properties - Part 4 resistivity

GB / T 12703.6-2010 Textiles electrostatic properties - Part 6 fiber leakage resistance

GB 13348-2009 safety rules electrostatic liquid petroleum products

GB / T 15738-2008 conductive and antistatic fiber reinforced plastics resistivity test methods

GB / T 18044-2008 carpet electrostatic habits evaluation walking test

GB / T 18864-2002 vulcanized rubber products for industrial use antistatic and conductive resistance limits

GB / T 22042-2008 clothing antistatic properties of the surface resistivity test methods

GB / T 22043-2008 clothing antistatic properties resistance through a material （vertical resistance） test method

GB / T 24249-2009 anti-static clean fabric

GB 26539-2011 Antistatic Antistatic ceramic tiles ceramic tiles

GB / T 26825-2011 antistatic anticorrosive plastic

GB 50515-2010 guide （anti）-static floor design specifications

GB 50611-2010 antistatic electronic engineering design specifications

GJB 105-1998-Z electronic products against electrostatic discharge control manual

GJB 3007A-2009 anti-static work area technical requirements

GJB 5104-2004 Radio Fuze hood hood with anti-static coating and electrostatic properties General requirements

Fourth, the volume resistivity Surface resistivity tester technical indicators

1 resistance measurement range: 1 × 104Ω ~ 1 × 1018Ω, divided into ten range.

2 current measurement range of 2 × 10-4A ~ 1 × 10-16A

3 all-digital LCD display.

4 Accuracy: Accuracy is better than the following table:

Effective Range Display 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 from 0.01 to 19.99 5% +2 digits

1011 from 0.01 to 19.99 5% +2 digits

1012 from 0.01 to 19.99 5% +5 d

1013 0.01 19.99 10% +5 d

1014 0.01 19.99 10% +5 d

1014 above 0.01 ~ 19.99 10-15% +5 word

（Outside the valid display range errors are likely to increase）

Test current the same accuracy and resistance）

Test voltage accuracy is 10%

5 Use environment: Temperature -10 ℃ ~ 50 ℃ Relative humidity <90%.

6 Test voltage: DC10V, 50V, 100V, 250V, 500V, 1000V. ± 10%

7-powered forms: AC 220V, 50HZ, power consumption of about 10W.

8 Instrument Size: 300mm × 280mm × 150 mm.

9 Weight: about 3.0KG.

Five, terminology

1） Insulation resistance: is applied to the sample in contact with the second electrode of the DC voltage is divided between the two electrodes by the quotient of the total current. It depends on the volume resistivity and surface resistivity.

2） Volume resistance: the sample is placed on two opposite surfaces of two electrodes a DC voltage applied between the two electrodes and the flow through the quotient between the steady-state current; the current does not include current along the surface of the material. Be formed between the two electrodes is negligible polarization.

3） Volume Resistivity: insulation material inside the electric field intensity of the steady state current density, that is the volume resistance per unit volume.

4） Surface resistance: a surface of the specimen of the applied voltage between the electrodes after a certain time and the flow of current between two electrodes of the quotient; the current flowing through the primary current of the sample surface, but also part of the flow through the sample volume of the current component. Between the two electrodes

Possible formation of polarization is negligible.

Surface Resistivity: The surface layer of the insulating material of the electric field strength of the current density and the line, that is the surface resistance per unit area.

Six, measurement technology

a. Typically, the insulating material for electrical insulation between the various parts of the system and the insulation, the solid insulation material also acts as a mechanical support function. Material is generally desirable to have as high insulation resistance, and has suitable mechanical, chemical and heat resistance.

b. insulating materials generally have a high resistivity, the conduction current is very small. If you pay attention to the interference of external factors and the leakage current, the measurement results will change a lot of errors. While the insulating material itself and the environmental conditions change absorbency measurement results

Fruit also have a great impact.

c. impact test volume resistivity and surface resistivity of the main factors are temperature and humidity, electric field strength, so the charging time and the residual charge. Volume resistivity of the insulating material can be used as a parameter selected, the resistivity changes with temperature and humidity changes significantly. Body

Measurement of volume resistivity is often used to check the insulation material is uniform, or to detect but which can affect the quality of the materials can not be detected by other means to conductive impurities.

d. because the volume resistivity is more or less always included in the test to the surface resistance, thus only approximate measure surface resistance measured surface resistance value can represent the test sample is the degree of surface contamination. Therefore, the surface resistivity of the material itself is not a Characterization

Characteristic parameters, but a characteristic of the material parameters of surface contamination. When the surface resistance is high, it is often time changes in an irregular manner. Measuring the surface resistance is usually specified time of 1min electrification.

（1） Temperature and humidity: solid insulating materials insulation resistance increases with temperature and humidity is reduced, in particular the volume resistivity change with temperature change is very large. Thus, porcelain material not only to determine the volume resistivity at room temperature, but also measuring temperature

The volume resistivity, in order to assess the quality of the insulation properties. Large conductivity of the water, as humidity increases, the surface resistivity and has open porosity volume resistivity of the electrical ceramic materials drastically. Therefore, the determination should be strictly in accordance with the provisions of sample handling requirements

And tested environmental conditions.

（2） electric field intensity: When the electric field intensity is relatively high, the mobility of ions increases with increasing electric field strength, and also close to breakdown a large number of electron mobility, the volume resistivity greatly reduced time. Therefore, the measurement time, the applied voltage should not exceed

Predetermined value.

（3） the residual charge: the sample processing and testing process, it may generate static electricity, the higher the resistance the more prone to static electricity, affect the measurement accuracy. Thus, in the measurement, the sample to compley discharge, several electrodes can be short-circuited together.

（4） the elimination of stray electric potential: the insulation resistance measuring circuit, there may be some stray electric potential, such as thermoelectric power, electrolysis potential, exposure potential, of which the greatest impact on the potential for the electrolysis. With high resistance meter to measure the surface moist sample volume resistance when measuring

Protected poles between pole and can produce 20mv potential. Before the test should be checked for stray electric potential. According to the sample before and after pressurization of the secondary impedance meter indicates whether the same to determine whether stray electric potential. If the same proven spurious electrical potential; otherwise should look for troubleshooting and miscellaneous

Scattered potential causes can be measured.

（5） to prevent leakage current: For high resistive material can be removed only by taking protection technology leakage current measurement. Protection technology that is caused by measurement errors in the placement of protective conductor leakage path, stopped may cause measurement errors stray current,

So that does not flow through the measuring circuit or meter. Protective conductor connected together to form the protected side, usually protected grounded. Measure the volume resistance, protection of highly three-electrode system is to protect the conductors. This requires the guard electrode and measuring the surface resistance between the electrodes is higher than the sample

A resistor element connected in parallel with it 10 to 100 times. Line connected, you should first check whether there leakage. At this point disconnect power lines connected with the specimen plus voltage. If the measurement sensitivity range, the measuring instrument indicates the resistance value is infinite, then the line leak

Power, can be measured.

（6） conditional processing requirements and test conditions: the resistance of solid insulating materials with temperature and humidity increases. Sample pretreatment conditions depend on the material being tested, these conditions in the material specification. Recommended GB10580 "solid insulating materials under test

Test before and the use of standard test conditions "specified in the pretreatment method. Using glycerol - water pretreatment humidity chamber for humidity. Test conditions shall be as consistent as possible with the pretreatment conditions, in some cases （such as flooding treatment） can not maintain the pretreatment conditions and measurement

Consistent test conditions should be removed from the pretreatment environment after completion of the test in the shortest possible time, usually no more than 5 minutes.

（7） The electrification time requirements: If the DC voltage is applied to the sample in contact with two electrodes, the current through the sample to be exponential decay to a stable value. Decrease in current over time may be due to dielectric polarization and the movable electrode due to ion displacement. For

Volume resistivity of the material is less than 1010Ω · m, the steady state is usually reached within 1 minute. Therefore, the time to go through this after electrochemical measurement resistor. For higher resistivity material, current decreases in the process may last for minutes, hours, days, due to

This requires a longer period of time electricity. If desired, the volume resistivity can be used to describe the relationship and the time characteristics of the material. When the surface resistance is high, it is often time changes in an irregular manner. Measurement of surface resistance are generally required one minute electrification time

.

Seven, volume resistivity Surface resistivity tester Caution:

 Impedance measurement method must be used in strict accordance with Buju, otherwise it may cause permanent damage to the instrument or electrical people.

One should "Rx" zeroing when open at both ends connected to the resistor box or as measuring object when measured after zero will produce large errors. After zeroing in general once the test process without re-zero, but after changing the measurement voltage may have to re-zero.

2, prohibits the "Rx" short ends to avoid micro-current amplifier by the high current impulse

3, in the testing process should not arbitrarily change measure voltage, measure the voltage may be altered arbitrarily high voltage or current is too large damage the device under test or the test instruments, and some material is non-linear, ie, voltage and current is not consistent with Ohm law has changed

Alternating voltage is not linear due to the current change, so the measured resistance will change.

4, measured from the low-order profile and gradually pull toward a higher profile slightly reversed stay every 1 to 2 seconds to observe the display numbers, should be stopped when the displayed value, the current number of records that is, the measured resistance values. If "1", it indicates Underrange pull files should go higher. Until there was

Figures shown so far. When a show can not go down to the higher number allocated file, otherwise it may damage the instrument （the machine has over-current protection circuit）. In addition to 104 Ω stalls outside, when the display is less than 1.99, which means that over range should downshift!

5, most insulating materials, in particular anti-static material resistance value after the voltage there will be a number of changes caused by changes in the high resolution of the instrument, which will cause the end of the displayed value is changed by several orders, which not the instrument itself, but

Conductive object being measured is complex mechanism and makes some changes in resistance. In this case, the effective number often take two suffice.

6, after power, fingers can not touch the metal part of the high-voltage instrument has two roots line: high voltage （red） and micro-current test line. When used to pay attention to high-voltage lines, high voltage power future generations can not be touched in order to avoid electrical or hemp hand.

7, the test process can not touch the micro-micro-current test current test side by side fear or human induced voltage high current and electrostatic shocks. So in the boot and test process can not end in contact with the micro-current testing, in order to avoid damage to the instrument.

8, in the measurement of impedance should be used when the object to be measured shield shield box. In the measurement is greater than 1010 Ω or more, in order to prevent interference caused by reading unstable surface.

9, should be completed for each measurement range switch back to "104" file then the next test in the measuring range should gradually switch to high resistance range, the measurement range switch complete reversal should be low. To ensure that the next time you turn the range switch in the low resistance range file.

Body generally can bring thousands or even tens of thousands of volts electrostatic!

Eight, impedance measurement FAQs

1. Why is measuring the same object with different resistance ranges have different readings?

This is because the measurement of resistance in order to prevent over-voltage damage to the instrument, if there is over-range protection circuit inside the instrument to work, will test the voltage down to protect the inside amplifier. Measured at different voltages of the same object will have different results. And when measuring

If the resistance reading is less than 199, it is necessary only for the three-digit number and the first digit is 1, the accuracy to decline. Therefore, when measuring resistance when first reading becomes a reading from one, it should not go down to the higher range of the instrument caused by twisting the switch to prevent excessive current impulse

Blow. In actual use, the reading than the median number of bits less than the reading accuracy.

2. Why are some objects when the current measurement with different ranges measured results will appear larger difference?

This is because the general object is not a constant current output stream, and the instrument has a certain resistance, when the selected range on the instrument so that the resistance is too large voltage drop on the effect on the instrument when the output current of the measured object may cause measurement errors. Generally the smaller the current measuring range

The higher the resistance, so the current should be used in the measurement of large current range. In actual use, as long as a meter reading, the reading of the small number of bits less than the number of bits more accurate readings.

3. Why the measurement instrument reading is always unstable?

Generally the electric conductivity of the material is not critical as a standard sample in a certain voltage resistance are very stable under the current, there are many materials, especially anti-static material which does not comply with Ohm's law conductivity, so the readings instability in the measurement. This is not a problem of the instrument, but is

Measuring the performance of object decisions. Some standard requirements to measure 1 minute readings shall prevail. Usually in the measurement of high resistance or micro-current measurement accuracy because of the poor reproducibility of the measurement reading only require 2 or 3. Also in measuring large resistances if the shield is not

Good also due to external electromagnetic signal measuring instrument readings resulting instability.

4 This is because when the measured object and the measuring instrument has a certain input capacitance of this capacitor has been charged in the measurement to the measuring resistor the voltage value if the instrument does not turn off the power after the block 104 to position the charged The capacitor will instrument amplifier

Discharge caused by damage to the instrument. When the object being measured capacitance increases, the test voltage is higher, the greater the energy storage capacitors, more prone to damage the instrument, particularly in the high resistance range or low range when the current is very sensitive because of the instrument, the instrument overload damage

More likely. So be sure to dial to 104 gear range switch off the power before.

5. Why not change during the measuring resistance on the analyte test voltage?

If in the process of measuring the resistance to change on the analyte test voltage, regardless of the voltage becomes high or low when they will produce a large pulse current, the large current is likely to make the instrument over range or even damage the instrument. Other hand, if the sudden change in voltage will be through

The measured object （distribution） or reverse discharge capacitor discharge impact on the measurement instrument and damage equipment. Some objects of the pressure is low, when you have the right to change the voltage measurements can penetrate and produce high currents damage the instrument. If you want to change the measurement voltage, ensure that

Measuring object will not breakdown voltage is too high, the first switch 104 stalls will range after the power is turned off again from the instrument panel to adjust to the required voltage. Some materials are non-linear, voltage and current that is incompatible with the Ohm's law, the voltage is changed due to

Current change is not linear, so the measured resistance will change.

6. Why do you want to measure the complete range switch dial to 104 files after power off?

This is because the machine capacitor charged with a high voltage （maximum voltage of 1200V or more）, the power carried by these capacitors maintain a longer period of time, if you turn off the power switch, it will be quickly inside the high-voltage capacitor discharge , and not in the high-pressure side measuring

Leaving very dangerous voltages cause electrical shock. If only the dial instead of the power cord off the power at the beginning, although off the power supply, but also inside the machine due to prolonged high-voltage capacitors maintain high voltage, will be on staff or other objects cause electric shock or damage. The instrument in question

Do not open the case when the machine due to the high

Pressure cause an electric shock, the instrument is to find a professional technician or return to factory repair.

Nine, volume resistivity Surface resistivity tester main applications

impedance test measures a material such as Static （anti-static shoes, anti-static plastics and rubber products, anti-static floor computer room, etc.） resistance testing;

b Material Volume resistivity （rate） and surface resistivity （rate） measurements;

c electrochemistry and materials testing, as well as physics, optics and materials research;

d weak current measurement devices such as the photoelectric effect and dark current measurements.

Additional description:

Resistivity

Resistivity is used to indicate the physical resistance characteristics of various substances. Some material 1 meter long, cross-sectional area of ??1 square millimeter at room temperature （20 ℃ pm） resistance of the wire, called the resistivity of the material. Resistivity is measured in ohm-meters （Ω · m or

ohmm）, commonly used unit is ohm-mm and ohm meter.

Application

Lower resistivity material is called a conductor, the common conductor is the main metal, and the conductive nature best silver, followed by the semiconductor, silicon-germanium. When there is an external electric field, the metal in the movement of free electrons and lattice nodes constantly hot vibrator is made from

Collide with the child, so that electron movement hindered, thus it has a certain resistance. Other conductive materials easily such as glass, rubber, etc., high resistivity, commonly referred to as an insulator. Between the material between the conductor and the insulator （such as silicon） called semiconductors. Resistivity

Science symbol ρ （Rho）. The resistance of the object is known, by resistivity ρ, length l and cross-sectional area A calculated: ρ = RA / I, in the formula, the resistance R in ohms, the length l in meters, cross-sectional area A in square meters, unit of resistivity ρ

Ohm-m

The formula

Resistivity is calculated as: ρ = RS / L

ρ is the resistivity - common units Ω · m

S is the cross-sectional area - common units ㎡

R is the resistance value - common units Ω

L is the length of the wire - common in m

-----------------------------------------

Another resistivity is calculated as: ρ = E / J

ρ is the resistivity - common units Ω · mm2 / m [1]

E is the electric field strength - Common units N / C

J is the current density - Common units A / m

（E, J be the vector）

Explanation

1. And the conductor resistivity ρ of the material only, but also on the temperature and the conductor. Little change in the temperature range: Almost all metals resistivity changes linearly with temperature, that is ρ = ρo （1 + at）. Where t is the Celsius temperature, ρo is the resistivity O ℃, a

Is the temperature coefficient of resistivity.

2. Since the resistance change with temperature change, so for some electrical resistance, which must indicate their physical state. If a 220 V -100 W lamp filament resistance is 484 ohms when power is not energized only 40 ohms.

3. Resistivity and resistance are two different concepts. Resistivity material on the current hindered reflect the attributes of objects on the current resistance is hindered reflecting properties.

Summary:

Under normal （from the table） in order, the best conductivity of silver, copper, aluminum, which is the most common three materials, often used as a conductor, of which the most widely used in the copper, the wires are now almost Copper （precision instruments, except for special occasions） aluminum due

Chemically unstable prone to oxidation has been eliminated. Because aluminum density, drawn wide, and the price cheaper than copper, is now widely used in power transmission system overhead electricity transmission lines. In order to solve insufficient rigidity aluminum defects, generally ACSR, namely

Aluminum wire coated with an internal steel wire to improve strength. Silver conductive best performance, but because of the high cost of rarely used, and only in high demand situations was only used, such as precision instruments, high-frequency oscillator, aerospace and so on. By the way gold contacts on the instrument in some cases

Also useful for gold, it is because gold is chemically stable so the use of, not because of its small resistivity due.

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Service and Warranty:

Over the years, our company has been specializing in the production of electrical test equipment, through research, exploration, summed up a complete product service support system, to provide users with high-quality and timely pre-sales, after-sales service

To create brand, enhance their visibility and establish a corporate image, our spirit of "all the pursuit of quality, customer satisfaction for the purpose of" spirit, "the most preferential prices, the most attentive service, the most reliable product quality" principle You solemn promise:

A commitment to product quality:

1, I need to provide to ensure that the original production equipment, and factory data accessories complete. In order to maintain the normal operation of the contract and maintenance of equipment, I guarantee to provide technical information and drawings are complete, clear and correct.

2, product manufacturing and testing are quality records and test data.

3, the product performance testing, we sincerely invite users to visit the product of the whole process, all performance checks, was confirmed to be eligible after the boxed product shipped.

Second, the product price promise:

1, in order to ensure high reliability and advanced systems were chosen selection of quality brand-name domestic or international.

2, in the same competitive conditions, our company not to reduce product performance, change the product on the basis of the cost of parts, in good faith in the most favorable price to your side.

Three: installation, commissioning and acceptance of commitments:

1, to assist with the installation, responsible for equipment transport and commissioning.

2, the device according to order technical annex for acceptance. Final acceptance for the purchaser, the user-supplied samples to test and provide test reports.

3, installation and commissioning while operating the instrument off-site training of operators free 2-3, the operator should be selected by the demand side of the long-term stability of staff training to the basic principles of the equipment, software, use, operation, maintenance matter of understanding and application of the

Devices are able to operate independently of the sample detection, analysis, and can carry out basic maintenance.

Fourth, warranty:

1, the device year warranty and lifetime service within one year of non-human damaged parts replaced free of charge during the warranty period the user received an invitation, at the latest within a response time of 2 hours, after the failure with user confirmation, I will 48 hours to send engineers arrived at the scene

Free service as soon as possible to identify the fault location and cause of the malfunction, failure to promptly report the reasons for users and exclusion methods.

2, man-made damaged parts during the warranty period by purchasing （processing） prices charged replacement.

3, the warranty period to continue to provide users with high-quality technical services, the user received within 3 days after repair invited to send engineers to reach users on-site repair. And enjoy the preferential treatment of purchased parts.

4, the sensor and the whole circuit overload overpressure damage is not covered under warranty.