Schiller CARDIOVIT AT-2, Руководство по обслуживанию

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Page 5.9
Chapter 5
Adjustments
SCHILLER AT-2 6-Channel ECG Unit
SERVICE HANDBOOK Issue 2.1 November 1998
Service Printout
The service printout provides information of the patient cable and electrodes and gives the value
of certain reference voltages and important internal offset values. These values are for information
only. The service printout also gives variable settings and measurements that can be set by the
service engineer; to carry out these adjustments some of the settings require additional test
equipment. To obtain the service printout press the following key sequence:
ALT - 0 - 3 - any number 0...6
ECG Reference Voltage This provides measurements and setting facilities for the
reference voltage used for accurate measurement of ECG
signals
• Uref + This gives the value of the reference voltage
used in the multiplexer circuit on the ECG Amplifier.
The value of the reference voltage is 2000 mV ±20 mV.
• Uref - This is a negative reference voltage used on the
ECG Amplifier board. The value of this voltage should
be -2000 mV ±20 mV.
• Udif This is the sum of the two reference values above
(Uref +and Uref -). This value must be 4000 mV ± 20
mV.
• Uoff This is the value of offset voltage on the
multiplexer circuit. This value should be in the range ±
150mV
• Calib This value is the Udif value divided by 4. The
nominal value is 1000 ±5 mV.