Latch-Up Watcher Check; Measuring Noise On The Input And Baseline Checking; Checking Time-Constant - Innomed Medical Heart Screen 60G Service Manual

Innomed Medical

8.3.3 Latch-up watcher check

Only connect the DC generator to the amplifier input according to the table. The DC level has to be controlled between
0 and 450 mV. The filter must be turned off.
Connect the patient cable according to the following table and start the channels one-by-one with the channel selector.
On the display check the measurement order quality, the baseline, which can be reset after DC controlling with the
blocking command.
During the examination the device indicates the latch-up watcher circuit's operation with text message. During the
measurement enter the DC values into the table where the text appeared. The comparison levels must be min. 340 mV,
max 450mV.
P1
L all other
R all other
V1 all other
V2 all other
V3 all other
V4 all other
V5 all other
V6 all other

8.3.4 Measuring noise on the input and baseline checking

Make a 10 seconds long recording with the shorted inputs at *2 sensitivity, 25 mm/sec speed from all groups. The
filter must be off. Short the device input. Measure the noise and absolute deviation from the baseline on the null-line.
The noise on the input is acceptable if the value of the noise peak-to-peak is not greater than
(0.4 mm+1 pixel)=0.525 mm on any lead. The null-line is acceptable if the deviation from the baseline is less than 2
mm anywhere on the printout and on the display.

8.3.5 Checking time-constant

Apply 4 mVpp 0.05 Hz sine signal onto the amplifier's input from a ground independent generator according to the
table. Set amplifier sensitivity to *1/2. Start on-line recording with 5 mm/sec speed and measure the time-constant on
the printout. The time-constant must be min. 3.2 seconds.
P1
L
R
F
V1
V2
V3
V4
V5
V6
2014.01.09
Heart Screen 60G-80G-L
P2 Examined lead
I
II
V1
V2
V3
V4
V5
V6
P2 Examined lead
all other I
all other II
all other III
all other V1
all other V2
all other V3
all other V4
all other V5
all other V6
Positive DC (mV)
Measured time-constant
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Service manual
Negative DC (mV)