Innomed Medical
Heart Screen 60G-80G-L
Service manual
2014.01.09 29/84
D-5450-1-B_HS60G80GL_SM_ENG.doc
During measurement the PACE detector operation must be checked with the oscilloscope connected to the test
connection’s PACE output. TTL level impulses must be visible on the oscilloscope, which width is 100 (+/- 20%) ms
and appear with the PACE repeating frequency. The PACE tolerance and the detector operation must be checked on
all the leads with both positive and negative polarity.
P1
P2
Measured lead
Measured
differentiated
error value (
C
V)
Measured long term
error value (
C
V)
positive negative
positive negative
L
all other
I
R
all other
II
V1 all
other
V1
V2 all
other
V2
V3 all
other
V3
V4 all
other
V4
V5 all
other
V5
V6 all
other
V6
6.5.9 Checking amplifier latch-up watcher
Only connect the DC generator to the amplifier’s input according to the table. The DC level has to be regulated
between 0 and 500 mV.
Set the device to 1mV/cm sensitivity (x1) and 25 mm/sec speed.
Connect the patient cable according to the following table and start monitoring the individual channels one-by-one. On
the monitor check the measurement order quality and the baseline, which can be reset with the blocking command
after the DC regulation.
During measurement the latch-up watch circuit’s operation has to be checked with the oscilloscope connected to the
test connection’s PACE output. The PACE output is continuously high if the circuit can handle the DC applied to the
amplifier, and continuously low if the DC is overdriven. The comparison levels have to be at least 340 mV and
400mV.
If the levels are too high, they may be decreased by increasing R60-R67, and may be increased in reverse.
P1
P2
Measured lead
Positive DC
(mV)
Negative DC
(mV)
L
all other
I
R
all other
II
V1 all
other
V1
V2 all
other
V2
V3 all
other
V3
V4 all
other
V4
V5 all
other
V5
V6 all
other
V6
6.5.10 Noise measurement and baseline checking
Short all the inputs with a short-plug (without a patient cable) and measure the channels’ noise with the measurement
program running.
Set the device to the highest, 0,5mV/cm sensitivity (x2) and 25 mm/sec speed, with the filter off.
The noise cannot be greater than 20
R
Vpp.
