Medical equipment often needs to operate in a high-noise environment. In particular, electromagnetic interference can affect the accuracy and reliability of the equipment. Through the CMRR common-mode rejection ratio test, it can be known whether the DUT can effectively suppress the interference of common-mode signals, maintain signal purity and accuracy, and ensure patient safety and the accuracy of medical diagnosis.

CMRR 3.0E has double shielding of internal circuits and special external mechanism design to effectively isolate environmental noise. It can also be equipped with an external box to achieve higher test accuracy. Just as importantly, the design goal of CMRR 3.0E is to help customers increase the CMRR value, which can be as high as 120db, far exceeding the 89db required by the standard.

The strict requirements of the IEC 80601-2-26 standard are also one of the important reasons for the birth of CMRR 3.0E. The 100pF capacitor in the standard test circuit increases the difficulty and complexity of the test. CMRR 3.0E uses a 110MΩ/10MΩ 11:1 voltage divider and voltage measurement circuit to automatically measure the common mode point voltage Vc after 100pF, solving the dilemma of measuring Vc.

100pF also creates problems with patient cable placement. If the cable is placed on a ground plane, the stray capacitance between it and the ground will affect the test quality; if the height of the stray capacitance and the ground changes, it may affect the test results. To solve this problem, CMRR 3.0E has a built-in sine wave signal generator that can generate different test voltages and frequencies, including: 20, 2.828, 0.5 Vrms and 2 Vrms required for standard testing, making up for the external signal generator and voltage supply.

At the same time, to conduct testing more efficiently, we also provide a free Software Development Kit (SDK). Engineers can develop automated testing software by themselves and flexibly expand testing capabilities. Our exclusive Standard Assistant Software also helps improve the efficiency and quality of testing.

During the design process, we always focus on customer needs and are committed to providing a high-quality testing device that can truly solve problems and improve work efficiency. We believe that CMRR 3.0E will be a great help for customers to stand out in the highly competitive market.　

All-In-One Circuit Design to Overcome Testing and Technical Difficulties 

• Built-in calibrated sine wave signal generator solves the problem of insufficient voltage supply for general signal generators
• Built-in calibrated voltage measurement circuit, when adjusting the variable capacitor, it can simultaneously monitor whether the common mode point voltage Vc is half of the signal generator voltage Vs
• Built-in MCU and electronic relay, all RC lines and other voltage options can be switched manually or automatically 

High Common Mode Rejection Ratio Enhances Product Competitiveness

　

• Double mask structure to isolate internal and external noise interference

• Common mode rejection ratio under unbalanced testing can reach 111dB

• Optional shielding cover can be used to perform higher CMRR value testing

 

SDK for Flexibly Developing Programs as Needed

• Users can develop automated testing software based on their needs to control the testing process, reducing the effort of repetitive setups  
   

Standard Assistant Software for Effortlessly Conducting Compliance Tests

• Supports EEG-related international standard IEC 80601-2-26:2019 and Chinese regulations GB 9706.226
• Users can follow instructions step-by-step in the standard assistant software to configure the DUT, select parameters, and conduct compliance testing

*Note: The Standard Assistant Software needs a separate purchase.