6242D (0.001Ω to 1GΩ)

  • Range 0.001Ω to 100MΩ
  • Optional Range to 1G
  • 7” touch screen and USB
  • Accuracy < 10 x 10-8 for 1:1 ratios
  • < 10 x 10-8 for 10:1 ratios up to 10KΩ
  • Optional Accuracy < 5 x 10-8 for 10:1 ratios up to 10KΩ
  • Optional Accuracy < 5 x 10-8 for 1:1 ratios up to 10KΩ
  • < 7 x 10-6 at 100MΩ
  • Linearity < 5 x 10-9
  • Binary wound current comparator
  • Manual and Automatic Operation
  • Full system solutions and full system integration with 4200 series of Matrix Scanners and 6011 Range Extenders
Features & Benefits

Since its inception in 1987, MI has been providing customers with the best in resistance measuring equipment. As the original manufacturer of the Automated Direct Current Comparator (DCC) Resistance Bridge, MI has been the industry leader in providing the highest level of automated resistance bridges and turnkey systems to metrology laboratories worldwide. The 6242D Resistance Bridge is ideal for those laboratories involved in both resistance and temperature measurements that do not require the accuracy level of a national laboratory. There is no point in paying primary dollars for an application that doesn’t require primary specifications.

The AccuBridge® 6242D is ideal for measurements in both resistance metrology and temperature thermometer applications. With its innovative technology, the AccuBridge® 6242D’s speed, measurement accuracy, and data handling capabilities, make it the preferred primary resistance measurement system in primary and calibration labs worldwide. The 6242D is designed for flexibility and ease of use.

Ratio Range & Accuracy-

The AccuBridge® Direct Current Comparator with its binary wound current comparator technology balances current ratio with effective resolution of 25 bits. It provides ratio measurements with an accuracy to better than 10 parts in 10-8 with a linearity of better than 5 parts in 10-9. The 6242D can perform ratio measurements (Rx/Rs) with resistances valued from 0.001 ohm to 100 Mohms (or to optional 1Gohm Range).

A line of optional high current range extenders permits measurements down to 1 micro ohm for shunt resistance or DCCT measurement applications.

Full Featured Standalone or Automated Resistance Operation

The 6242D Bridge itself can ratio a standard resistor to an unknown resistor being tested. Optional 10, 16 or 20 channel scanners can be used individually or together to connect to up to 40 channels of ratio measurement for up to 40 different test resistors. See the 4200 Series technical data sheet.

The 6242D is perfectly suited for stand-alone operations or you can team it with MI’s AccuBridge® 6242SW Windows®-based Operating Software for fully automated measurements, history logging, graphing, and regression analysis. Standalone operation with the 6242D’s touch sensitive display panel provides full bridge capabilities to the operator. Ratio or direct resistance measurements can be made. Multiple measurements over time can be numerically displayed or graphically displayed to best fit the user’s needs.

The AccuBridge® family of bridges

The 6242D is a secondary performance model of an MI Bridge. One of a family of bridges where there are various bridges optimized for different tasks; from measuring Quantum Hall Resistance standards over a smaller range of resistance. There are three different bridge designs which use different measurement methods to measure over 21 orders of magnitude of resistance, from 1 micro ohm to 10 Peta ohms. The Accubridge family offers the best line of bridges available for measuring the widest range of resistance.

The 6242D is a completely redesigned Resistance Bridge using the new AccuBridge® Bridge technology from Measurements International in providing lower uncertainties, faster measurement rates and more operational capability. It incorporates the most technological advanced design and measurement features of any resistance bridge directed at the Primary or Secondary market.

The 6242D’s low-noise, touch screen display is interactive with the measurements, as shown in the following screen images. When a reading is complete, the average value and uncertainty (based on the number for statistics) are displayed. All uncertainty calculations are 2 sigma level.

Settings_Table Software_Graph Table

As a stand-alone device, the AccuBridge® 6242D measures both ratio and absolute values. You select functions using the menu on the 6242D’s large touch screen display. For absolute measurements, you enter the value and related uncertainty of the standard resistor (Rs) using the display’s keypad. You enter the measurement functions such as current through the unknown resistor, settle time, number of measurements, and number of statistics the same way.

Using the same AccuBridge® technology found in our newer AccuBridge® line of resistance bridges, the 6242D has more of the features metrologists have come to expect from an MI bridge. The resistance range as a stand alone unit is from 0.001Ω to 100MΩ with optional 0.05 ppm uncertainty and a 1GΩ measurement range. With the 6242D, the best in resistance metrology gets even better.

Measurements International provides world-class expertise in DC resistance metrology to national measurement institutes (NMIs), primary and calibration laboratories who need to achieve the lowest possible traceable uncertainty in their measurements and calibration equipment. As your accreditation and global support partner, MI helps ensure your competitive advantage by offering leading product knowledge and applications expertise through coaching, system design, implementation, calibration services, and ongoing expert support.

At MI, it’s not only about the equipment and science, it’s about what you
can do and the ease with which you can do it.

Automatic current reversal ensures that DC offsets and thermals are cancelled out during the measurement. The 6242D has a standard (Rs) input and an unknown (Rx) input for measuring the ratio of the two resistors. All resistor connections to the 6242D are made using 4 terminal connections. Calibration verification of the 6242D can be made by performing an interchange measurement at any ratio. The interchange technique works at all ratios from 13:1 down to 0.1.


Measurements International’s AccuBridge® 6242SW Windows®- based Operating Software features measurements automation, report generation, historical analysis, and tracking and correcting for resistor
drift rates. When you combine the 6242D with an MI IEEE-controlled 9400 Standard Resistor Oil Bath or 9300A Air Bath, you can automatically perform alpha and beta calculations on resistors under test.

You can export all data directly to Excel® for various test patterns or mainframe applications. Resistor baths (oil or air), instrument controllers, printers, system software, IEEE488 interface, installation, and
training are available for complete system packages.

When you use the 6242D in conjunction with our 6011D series of Range Extenders and 6100 series of Power Supplies, you can extend its range. Our Range Extenders include the 6011/150A (Figure 2)
with room for a 20 Channel Mtrix Scanner, 6011/200A, and 6011/300A modules. The range can be extended further to 1μΩ with our Model 6013M 400 Amp Range Extender, Model 6012M 2000 Amp
Range Extender, or Model 6014M 3000 Amp Range Extender.


See datasheet for specification table