更優(yōu)異的性能指標(biāo)
Fluke A40B 精密分流器包含14個(gè)低電感同軸分流器，測量電流范圍從0.1mA 至100A。主要用于在實(shí)驗(yàn)室測量交直流電流和校準(zhǔn)交直流電流轉(zhuǎn)換測量裝置。 A40B分流器的分流器內(nèi)部的物理結(jié)構(gòu)和元件的精密性保證了它的頻率響應(yīng)非常平坦，電阻值非常穩(wěn)定、準(zhǔn)確，具有出色的低自加熱功率系數(shù)和低溫度系數(shù)，可以用于直接測量電流從直流到100kHz，直流電流準(zhǔn)確度達(dá) 20 ppm，交流電流準(zhǔn)確度達(dá) 23 ppm，遠(yuǎn)遠(yuǎn)高于之前的所有分流器裝置。因此，現(xiàn)在精密電流測量可以直接根據(jù)分流器電阻值的換算，而不一定要使用傳統(tǒng)復(fù)雜的交直流轉(zhuǎn)換轉(zhuǎn)換方法了。

更廣泛的應(yīng)用
用A40B分流器和測量電壓儀器配合使用，可以直接測量交直流電流，校準(zhǔn)各種校準(zhǔn)器的電流功能，支持大電流跨導(dǎo)放大器的校準(zhǔn)。由于A40B相位偏移極低，這一特點(diǎn)對(duì)交流功率測量，尤其是非正弦波形的測量非常關(guān)鍵，可以在電能質(zhì)量分析和數(shù)字功率表的作電流采樣器獲得電流信號(hào)的幅值和相位。

更靈活的使用
A40B分流器的電壓輸出標(biāo)稱值為0.8V。相對(duì)于傳統(tǒng)的45/75 mV分流器，輸出電壓高，大大提高了信噪比，可以非常方便地配用精密電壓表或其他測量儀器，100A電流對(duì)應(yīng)的電阻為8mW，隨著電阻增加到80W，電流量程為10mA。另外，1mA的分流器有內(nèi)部有一個(gè)電池供電的緩沖放大器，可以驅(qū)動(dòng)輸出電壓，使得 800W 的分流電阻與測量裝置產(chǎn)生zui小的相互影響。
A40B分流器出廠附帶著可溯源的校準(zhǔn)報(bào)告。如客戶需要，可選購符合17025A標(biāo)準(zhǔn)要求的校準(zhǔn)報(bào)告。

Absolute accuracy
The following table shows the 1-year absolute accuracy specification stated at k=2, approximay 95 % confidence for the calibrated value. The specifications include 1-year stability, temperature effects over TCal ± 1 °C, and the measurement uncertainty of the calibrated value.
Shunt Nominal Current: Specification ± μA/A, TCal ±1 °C, ≤ 50 % RH 1,2,3,5
  DC 1 kHz 100 kHz
1 mA 20 55 150
10 mA 20 26 26
20 mA 20 26 26
50 mA 20 23 23
100 mA 20 24 24
200 mA 20 26 26
500 mA 21 27 28
1 A 21 27 31
2 A 21 27 48
5 A 21 31 71
10 A 26 37 92
20 A 26 43 113
50 A 32 55 144
100 A 35 65 174
1 The measured current is determined from: I = （V/Rcalibrated） ×
（1 + （AC-DCcalibrated/1,000,000））; where AC-DC calibrated is expressed in ppm.
2 Above 1 kHz interpolate the specification （si） between frequencies fupper and flower using:
si = slower + （fi – flower） × （supper – slower） ÷ （fupper – flower）
3 Add 20 μA/A if relative humidity is outside specification limits.
4 1 mA specifications apply with the battery charger disconnected.
5 Specifications assume no loading effects due to the voltage-sensing device. See Output Voltage Measurement – Loading Effects in the operating information. 

Maximum AC-DC Difference
Shunt Nominal Current: Maximum AC-DC Difference （± ppm）1,2
  1 kHz 100 kHz
1 mA3 53 150
10 mA 20 40
20 mA 18 30
50 mA 13 16
100 mA 14 27
200 mA 17 28
500 mA 17 21
1 A 17 23
2 A 17 44
5 A 23 69
10 A 28 98
20 A 37 150
50 A 47 180
100 A 60 300
1 Specifications indicate the maximum flatness deviation from dc, and include both measured AC-DC difference and the uncertainty of measurement. They are stated at k=2, approximay 95 % confidence.
2 Includes 1-year stability of the AC-DC difference.
3 Specifications for the 1 mA current shunt are for TCal ± 1 °C. 

General Specifications
Dimensions （maximum） Shunt Value: 1 mA to 2 A
Height: 70 mm （2.75 in）
Width: 70 mm （2.75 in）
Overall Length1:
124 mm （4.9 in）
Shunt Value: 5 A to 20 A
Height: 130 mm （5 in）
Width: 130 mm （5 in）
Overall Length1:
210 mm （8.25 in））
Shunt Value: 50 A and 100 A
Height: 200 mm （7.9 in）
Width: 200 mm （7.9 in）
Overall Length1:
343 mm （13.5 in））
1 Includes input and output connectors; subject to change by component vendor.
 
Physical/mechanical parameters Shunt Value: 1 mA to 20 A
Weight: 0.7 kg （1.6 lb）
Input Connector: Type-N （female）
Output Connector: Type-N （female）
Shunt Value: 50 A and 100 A
Weight: 3.4 kg （7.5 lb）
Input Connector: Type-LC （female）
Output Connector: Type-N （female）
 
Operating environment Temperature: 13 °C to 33 °C
Calibration temperature （TCal） range:

18 °C to 28 °C
Humidity range for best specification 1,2:
≤ 50 % RH
Altitude: 0 m to 3,000 m

1 Resistance stability is affected by humidity, but changes are reversible.
2 If the shunts are calibrated outside this RH, stability specifications will be met as long as the shunts are stored and used at the same relative humidity ± 10 % RH.
 
Storage and transit environments （for models other than the 1 mA current shunt） Temperature to avoid damage:
-20 °C to 140 °C
Temperature and humidity to maintain performance1:

5 °C to 45 °C; 15 % to 80 % RH
Non-operating altitude:
0 m to 12,000 m

1 Storage at extremes of temperature or humidity will cause a temporary change of shunt resistance by up to ± 20 ppm. When subsequently stored or used within the limits of the operating environment, the shunts will recover to their original resistance value within 30 days.
 

Additional 1 mA current shunt specifications
Output resistance 8 m?
 
Maximum safe output current 11 mA （e.g., 1 V output into 90 ?）
 
Maximum capacitive load 800 pF
 
Output voltage regulation 15 ppm/100 pF
 
Maximum output dc v offset ± 100 μV （typical ± 25 μV）
 
Typical error @ 1 MHz < 2 %
 

Battery specifications
Battery size AAA （44.5 mm x 10.5 mm）
 
Battery technology Nickel-Metal Hydride （NiMH）
 
Number of batteries required 8 （in 2 groups of 4）
 
Nominal battery voltage 1.2 V （4.8 V per group of 4）
 
Typical battery capacity 800 mAh
 
Storage and transit environment to preserve the batteries Less than 90 days: -20 °C to 40 °C
Less than one year: -20 °C to 30 °C
Charging time （from fully discharged）: 100 minutes
 
Maximum operating time between charges Maximum output load （11 mA）:
18 hours
High impedance load: 24 hours
Recommended cooling period: 100 minutes
To prevent loss of battery capacity recharge at least twice per year.