Schiller CARDIOVIT AT-1, Руководство по обслуживанию

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Service Printout
The service printout provides information about the patient cable and electrodes and
gives the values of certain reference voltages and important internal offset values.
These values are for information only. To obtain the service printout press
ALT - 0 - 3 - 3
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 the offset voltage on the multiplexer circuit.
This value should be b150mV and - 150mV.
• Calib This value is the Udif value divided by 4. The nominal value is
1000 ±5 mV.
Electrode dc offset This gives the voltage drop in the patient cable and can
indicate any faults in the patient cable or patient electrode.
The value given is the dc voltage between the left leg electrode
and all other electrodes. The measurements obtained will
indicate any cable short circuits or open circuits. The measured
voltage value will depend on where the electrodes are
connected. The voltage readings that can be expected are
as follows:
•
With patient connected: ± 100mV
• With patient simulator connected: ± 20 mV. This will
depend on the patient simulator used and must be taken
as a flexible measurement.
• With all electrodes shorted together: ± 20 mV
• No patient cable connected: -350 to -450mV
TPH TEMP This is the measured ambient temperature that the processor
uses to correct print quality.
This reading should be ambient temperature ± 5
o
.
EPROM This is the checksum for the EPROM. Its value varies from one
software version to another.