Fukuda Denshi VaSera VS-1500, Service Manual

Page: 81 / 216

Chapter 5 Maintenance
Confidential Copying Prohibited
5-49
Item Inspection Item Procedure Criteria
1 Sensitivity
(1) Select [Calibration Device Auto] on
the SG-2000 and apply a standard 1 mV
test voltage to check sensitivity 1 of
record amplitude.
(2) Switch sensitivity to 1/2, 1/4 and 2
and check record amplitude.
(1) Record amplitude must be
10 ±0.2 mm or less
(2) Each sensitivity must be
±5% or less
2 Time constant
Select [Calibration Device Manu.] and
apply a 1 mV step signal. Measure the
time it takes to reach 37% amplitude. This value must be in the
range 3.2 to 3.84 s
3
Frequency
response
Select [High Frequency Spot] on the
SG-2000 and add a sine wave voltage to
the input. Set the record amplitude of 10
mm at 10 Hz as 100% and measure the
amplitude at 0.67 Hz, 40 Hz, 100 Hz and
150 Hz. Make sure the following
amplitudes are obtained:
0.67 Hz: +5, -10%
40 Hz: +5, -10%
100 Hz: +10, -30%
150 Hz: +10, -50%
4
Common-mode
signal
suppression
Select [Common-mode Signal] to enter a
50 Hz or 60 Hz 20 Vrms signal. Measure
the lead deviation at sensitivity 2. Record amplitude should be
4.0 mmp-p or less. (103 dB
or more)
5
Polarization
voltage
Select [Offset Voltage] on the SG-2000
and measure record amplitude when a 1
mV standard waveform is superimposed
on a ±550 mV DC voltage. Record amplitude must be 10
±0.5mm or less. (Changes in
record sensitivity must be 5%
or less)
ECG
6 Internal noise
Select [Noise Level] on the SG-2000 to
measure lead noise level at sensitivity 2. Noise level must be 0.4
mmp-p or less.
(Input conversion must be 20
µVp-p or less)
1
PCG filter
characteristics
(PWV)
Input sine-wave signals to the PCG
connector to measure the amplitude at
165 Hz and 280 Hz when an amplitude
of 10 mm at 200 Hz is 100%. Must be 70% or greater.
PCG
2
PCG filter
characteristics
(L)
Input sine-wave signals to the PCG
connector to measure the amplitude at
30 Hz, 50 Hz and 80 Hz when an
amplitude of 10 mm at 100 Hz is 100%. 50% or more at 30 Hz
70% or more at 50 Hz
90% or more at 80 Hz
1
Frequency
response
Input a 10 Hz sine-wave signal to the
Pulse Wave 1 and 2 connectors to
measure the amplitude at 0.5 Hz and 20
Hz when a 10 mm amplitude is 100%. The following ranges must be
met:
0.5 Hz: 90 to 105%
20 Hz: 71 to 105%
Puls
e W
av
e 1/2
2
Transient
characteristics
Input a 0.05 Hz step voltage to the Pulse
Wave 1 and 2 connectors and measure
the amplitude 2 s later. Deviation after 2 s must be
37% or more.
●
Status Check
Item
Inspection Item Criteria
1 ECG electrodes
LOF mark shall be displayed when electrode is
detached.
2 Backup battery It shall be 2.2V or more
3 Thermal print-head temperature
It shall be within the room temperature
±
10
°
C
4 Paper tray status
OPEN/CLOSE status should be properly
displayed.
Status
Test
5 Mark sensor
When a mark is detected on the paper, “Black”
should be displayed.
Press the
(Menu) key to open the [Top Menu], then touch [Initial Setting/Maintenance] Æ
[Maintenance]
Æ
[OK (
↵
)]
Æ
[Status] to open the [Status] window.