MECG 2.0 Test System | User Manual
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calibration, and can calibrate the offset value of the device within the original
specification of Whaleteq. Under normal use, the device is recommended to be
calibrated once a year. Please refer to the contact information and contact
Whaleteq for the original calibration service.
Note
: If Whaleteq detects that the components of the device are damaged and
makes it impossible to adjust, it shall be sent back for maintenance.
5.1 Self-Calibration
Self-calibration assists the user calibrates MECG 2.0 before testing.
⚫
Output Voltage Confirmation
Accuracy requirement specification
IEC 60601-2-25:2011, Clause 201.5.4 cc) requires that voltages applied are
accurate within ±1%. Since no minimum limit is stated (and it is impossible to
apply ±1% for very small voltages), WhaleTeq has applied a rule of 20% of
the EUT limit. This is effectively ±5µV for up to 500µV, ±8µV from 500 to
800µV and ±1% for values above 800µV. All values are taken with respect to
the baseline.
Overview/ Explanation
Please contact WhaleTeq for obtaining the PC software with “calibration
mode”, which produces a slow 0.1Hz square wave with an amplitude as set
on the display. For example, with 0.2mV setting, the output will slowly cycle
between 0.000mV and 0.200mV, changing every 5s.
User shall confirm that the value is the same as set on the screen using a
precision multimeter of accuracy equivalent to the Fluke 8845A
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. To eliminate
the effect of small dc offsets (which are not relevant to ECG equipment), the
meter should be zeroed during the time in which a nominal 0.000mV is output
(time in which the value is close to 0.000mV).
Each of the 8 outputs must be tested individually (LA, LL, V1 ~ V6), using RL
as the reference. For V1~V6, the output will be 5/3 (1.6666…) higher than the
setting, due to Wilson Terminal offset. For example, a setting of 5mVpp will
result in an output of 8.333mV.
During shipping, the full values of 0.5, 1, 2, 3 and 5mV with both negative and
positive values a checked (a total of 5 x 2 x 8 = 80 points). For regular
calibration, the user may limit the check to +2mV and +5mV (total 2 x 8 = 16
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The Fluke 8845A has an accuracy specification equivalent to ±3.5µV on the 100mV range which is
suitable for this calibration.
