Since its introduction in 1993, MI’s 6011 series of range extenders has earned a worldwide reputation for performance, dependability, and quality, and as a result, it is the range extender of choice for electrical calibration throughout government and industry. The model 6011 uses the ratio of two windings on a DC Current Comparator (DCC) to measure the ratio of two currents. The 6011 series of products are used to divide high currents down to workable levels. Measurements International is the only commercial laboratory that can provide accredited ratio calibrations to 0.2 ppm.
Today, the 6011 series of range extenders offer even more. In addition to dependability, simplified calibration, ease of use, automation and worldwide support, the 6011 is the best and only Range Extender that offers complete automation with uncertainty specifications that rival anything available on the market today. Customers can get all the performance they need to calibrate their most demanding workload. Typical applications are shown below for current source calibration using the 6511D with its built-in current source to 10 A (Fig 1) and the 6011D with an external current source, model 6150. (Fig 2).
The 6011 series of Range Extenders are also used to extend the range of the world’s number one resistance bridge, the MI 6010 or 6242 for calibrating shunts and DCCTs with better accuracy as compared to using a DMM. This new series of range extenders provide customers with flexibility in cost at the highest precision available on the market today. These are real solutions that address both current and future workload solutions while addressing the ever-tightening budget constraints.
At MIL, it’s not only about the equipment or the science…it’s about what that will enable you to do, and the ease with which you can do it.
There are several models available including the 6511D/10, 6011D/150, 6011D/200 and 6011D/300. As a stand-alone unit, the 6011D has front panel push-buttons for selecting the ranges and reversing the current or it can be controlled using the IEEE-488 interface bus. Current ranges can be selected by pressing the 10, 100 or 1000 ratio keys. Each model has a built-in reversing switch which can be reversed by pressing the Normal/Reverse key.
The precision DCC in the and 6011D uses a two-core magnetic modulation technique in a feedback loop to generate a secondary current. This secondary current is further modified by a circuit, which monitors the primary current and the turn’s ratio of the comparator toroid. Together, these two circuits create an effective loop gain in excess of 107 which forces the secondary ampere-turns to be equal the primary ampere-turns to better than 0.02 ppm, thus, making the instrument act as a precision DC Current Transformer. Offsets and thermals of the DCC are removed by reversing the Ix current. All connections to the 6511 and 6011 series of range extenders are made on the rear panel.
The Ix and Rx connectors have full current inputs (150 A/300 A) as well as 30 A inputs. This means that if you are using the 6011D at currents below 30 A it is not necessary to use the high current cables.
Calibration of the 6011D
The 6011D is a ratio device, the ratio being determined by Nx/Ns where Nx=1, 10 or 100 turns and Ns=1000 turns for ratios of 1000, 100 and 10. A ratio calibration technique is used to calibrate the 6011D using the stable ratio of standard resistors and the 6010 or 6242 resistance bridge as the reference.
A single output for the range extender is located on the rear panel. For current source calibration, a standard resistor between 1 ohm and 100 ohms (Fig. 1 and 2) can be connected across the output where a DMM can be used to read the voltage across the resistor. A Measurements International series 6150 (150 A) or 6250 (300 A) power supply can be supplied in a rack with the 6011D/150 or 6011D/300. The drivers for the Keysight series of 6600 current sources are also included in the MI supplied software.
The input and output currents for the 6011D are shown in the specification table. The full-scale output current of the 6011D/150 is 100 mA on range 10 and 100 and 150 mA on range 1000. Full-scale output current for the 6011D/200 and 6011D/300 is 100 mA on all ranges.
For complete automation of several 30 A shunts see our 20-channel 4220/30 four-terminal 30 A matrix scanner.
6011D Range Extender Applications
Shunt calibration or DCCT calibration can be performed using two precision DMM’s to compare the shunt or DCCT output voltage with the voltage across the standard resistor (Fig 4 and Fig 5). Automated software can be supplied (model 6300) to configure the system for automated Shunt and DCCT measurements up to 3000 Amps. For more accuracy, the 6010 or 6242 may also be used in place of the DMM’s to calibrate shunts and DCCTs as shown in Figure 6 & Figure 7.
The 6511D Range Extender and the 6011D Range Extender (Figure 7) may also be used in conjunction with MI’s model 6010D or 6242D Resistance Bridges and the MI 6150A (max 150 A) and 6250 (max 300 A) Power Supplies or the Keysight Technologies 6600 series of DC Power Supplies.
|Ratio||1000, 100, 10||1000, 100, 10||2000, 200, 20||3000, 300, 30|
|Max Input Current (A)||10, 10, 1||150, 10, 1||200, 20, 2||300, 30, 3|
|Output Current (mA)||10, 100, 100||150, 100, 100||100, 100, 100||100, 100, 100|
|Resistance Range||1 mΩ to 100 mΩ||100 µΩ to 100 mΩ||10 µΩ to 100 mΩ||10 µΩ to 100 mΩ|
|Linearity||< 0.02||< 0.02||< 0.02||< 0.02|
|Accuracy (ppm)||0.5, 0.2, 0.2||0.1, 0.1, 0.1||0.2, 0.2, 0.2||0.3, 0.2, 0.2|
|Output Compliance (V)||22||22||22||22|
|Operating Environment||18 °C to 34 °C||18 °C to 34 °C||18 °C to 34 °C||18 °C to 34 °C|
|Warranty||2 years||2 years||2 years||2 years|
Note 1: 6511D has a built-in 10 A power supply. 6011D/150 uses the 6150A and 6011D/300 uses the 6250A. External supplies offered are the Keysight Technologies 6600 Series.