Electrical safety tester CMRR 3.0+

signalvoltagefor electrocardiograph

Overview
The CMRR 3.0+ is a dedicated tester for measuring the Common Mode Rejection Ratio (CMRR) of ECG and EEG devices. Designed for medical hardware development, compliance testing and production-line verification, the instrument integrates double-layer shielding, a calibrated sine-wave signal generator and a voltage measurement circuit. It supports extended common-mode voltage output up to 70.71 Vrms, enabling CMRR testing ranges up to 120 dB. The device facilitates compliance testing with international and national standards including IEC 60601-2-25, IEC 60601-2-27, IEC 60601-2-47, IEC 60601-2-26, GB 9706.225, GB 9706.227, YY 9706.247, GB 9706.226, YY1079, YY1139, YY0782, YY0885, ANSI/AAMI EC11 and ANSI/AAMI EC13.

Functions

• Built-in calibrated sine-wave generator and voltage measurement circuit for accurate output and real-time monitoring of common-mode voltage (Vc).
• Double-layer shielding to minimize internal and external interference during sensitive measurements.
• Wide voltage range: standard outputs 0.5 Vrms, 2.828 Vrms, 20 Vrms, 2 Vrms and extended output up to 70.71 Vrms to support CMRR evaluation up to 120 dB.
• Touchscreen interface for selecting electrodes and toggling impedance simulation; mechanical knobs for fine capacitance adjustments to meet target measurement conditions.
• Onboard MCU and electronic relays allow manual or automated switching of RC circuits and voltage options.
• SDK provided to integrate automated test routines for production-line throughput.
• Optional Standard Assistant Software simplifies configuration of standard test items into guided steps for compliance testing.

Highlights

• All-in-one circuit design reproduces required test circuits including capacitance simulation and imbalance circuits to address common testing challenges.
• Integrated calibrated sine-wave generator overcomes insufficient voltage supply from general-purpose signal generators.
• Built-in calibrated voltage measurement enables real-time comparison of common-mode voltage (Vc) with signal generator voltage (Vs).
• Double-layer shielding and optional shielding covers improve achievable CMRR performance.
• Achieves up to 111 dB CMRR in unbalanced tests; shielding covers can extend measurable CMRR further.
• Provides SDK and optional Standard Assistant Software to automate tests and streamline compliance procedures.

Ordering / Package contents

• Part No. 100-CM00003 — Model: CMRR 3.0+ — Advanced common mode rejection ratio tester with 11 compound terminals.
• Package contents: CMRR 3.0+ x 1; Top shielding cover x 1; Bottom shielding cover x 1; Compound terminal x 11; USB cable x 1; Grounding wire x 1; 12V Power adapter x 1 (power cord excluded).
• Optional Software Add-on Pack part numbers and descriptions: HA0-CM04001 (Auto setup for IEC 60601-2-25 / IEC 60601-2-27 / IEC 60601-2-47), HA0-CM04002 (Auto setup for YY0782 / YY0885 / YY1079 / YY1139 and ANSI/AAMI EC11 / EC13), HA0-CM04003 (Auto setup for IEC 60601-2-26), HA0-CM04005 (Auto setup for GB 9706.225 / GB 9706.227 / YY 9706.247 / GB 9706.226).
• Optional Accessory: Part No. 100-CM00005 — Model: CM30ESBX — External shielding case (30 x 20 x 13 cm) for improved Holter shielding performance.
• Optional Calibration Service and Warranty Extension: Part No. YY0007 (Model C3) provides 3 years calibration service with recommended 1-year calibration interval; Part No. YY0008 (Model R3) extends limited warranty from 1 year to 3 years.

Technical specifications

• Supply voltage outputs: 0.5 / 2.828 / 20 / 2 / (70.71) Vrms — accuracy ±1%*.
• Common-mode point voltages: 1.414 / 10 / 1 / (35.355) Vrms — ±1% (0.25 Vrms ±2%).
• Frequency options: 50 / 60 / 100 / 120 Hz — ±1%.
• Electrode with impedance: selectable via touchscreen — options: None / RA / LA / LL / V1 / V2 / V3 / V4 / V5 / V6 / ALL.
• Electrode without impedance: selectable via touchscreen — options: RA / LA / LL / V1 / V2 / V3 / V4 / V5 / V6.
• Imbalance resistance R: 51 kΩ — 51 kΩ ±1%.
• Imbalance capacitance C: 47 nF — 47 nF ±5%.
• DC offset: powered by replaceable preinstalled battery; can be applied on RA / LA / LL / V1~V6 — 300 mV ±1%; battery life up to 40 hrs with intermittent use.
• 100 pF capacitor: measured indirectly using 11:1 (110 MΩ : 10 MΩ) voltage divider — 100 pF ±5%.
• Environment: intended for normal laboratory conditions. Operating temperature 15 - 30°C; relative humidity 10 - 75% RH. Note: 110 MΩ divider may be affected by humidity >85%.
• *Requires measurement with a higher-accuracy multimeter for stated accuracy.