Service Manual Ponygraphic
Chapter 6
Service Procedures
6.4
6.2.2. Flow measurement Check and Calibration
Carrying out a VC test and verifying the real-time curve displayed on the LCD screen can easily
check the flow measurement. The flowmeter is working substantially properly if:
1. The volume/time curve follows the ventilatory pattern both during expiration (pixels
drawn from up to down) and inspiration (pixels drawn from down to up).
2. The Volume/time curve is regular and doesn't present peaks or clipped edges (see
figure below)
Slow Vital Capacity
-4
-3
-2
-1
0
1
2
3
4
Time (sec)
Volume (l)
Peak
INSPIRATION
EXPIRATION
Clipped Edge
For further information Refer to the Pony graphic User's Manual on “turbine calibration.”.
6.3.
Auto Test Mode
Auto Test Mode
In the EPROM of the Pony graphic is stored an Auto-test program that is particularly useful to
check eventual malfunctions of the main components.
The program can be activated by switching-on the Pony graphic Unit while a special adapter is
connected to the RS232 port.
The electrical diagram of the Auto-test-adapter is shown in the following figure.
Dsr
Rx
Gnd
Tx
Check Clock
Check RAM
P1
CONNECTOR DB9M
5
9
4
8
3
7
2
6
1
R1
10K
R2
10K
D2
LED
D1
LED
Dtr
The adapter can be easily constructed or contact COSMED directly to procure it.
6.3.1. Running the Auto-test program
1.
Switch off the Pony graphic Unit
2.
Insert the Auto-test Adapter in the serial port of the instrument
3.
Switch on the Pony graphic and verify the LEDs on the Auto-test adapter
The Pony graphic Unit runs a self-test routine in order to verify the integrity of the
•
Serial Communication,
•
RAM access and
•
The clock function
The results of these tests are prompted with glowing of the 2 LEDs of the Auto-test Adapter
(refer to the electrical diagram above reported):
D2 switched on
Serial Communication OK
D2 is switched OFF
RAM Access OK
Test menu is prompted on the display CLOCK Functions OK.
