METRON QA-1290, Руководство пользователя и обслуживания, Страница: 39 / 65

7. Calibrating QA-1290
This chapter covers procedures for calibrating QA-1290. This is a
rather simple task, since only the pressure sensor circuit needs cali-
bration. The unit must be opened to perform the calibration.
WARNING!
HIGH VOLTAGES ARE CAPABLE OF
CAUSING DEATH!
USE EXTREME CAUTION WHEN PERFORMING TESTS AND CALI-
BRATION. USE ONLY INSULATED TOOLS WHEN THE UNIT IS
PLUGGED IN, AND THE CASE HOUSING IS OFF.
7.1 Calibration
1. Required Calibration Equipment
•
Digital voltmeter, e.g. Fluke 87
•
Pressure calibration instrument, e.g. Drück DPI-601
IMPORTANT!
BEFORE TESTING
THE QA-1290 MUST BE POWERED ON FOR AT LEAST 30 MIN-
UTES PRIOR TO CONDUCTING ANY TESTING.
2. Offset Adjustment
a. Connect - lead of voltmeter to T150 on the QA-1290 board
and the + lead to T151.
b. Power up the unit and stop at the zero adjustment menu.
c. With a screwdriver adjust R101 (offset adjustment) until the
voltmeter displays 0.000V (5mV. The display on the QA-
1290 shall read 0.
4. Gain Adjustment
a. Enter the "LEAK TEST" menu.
b. Connect the pressure pump to the cuff connection.
c. Reset pressure pump display to zero.
d. Pump up the pressure to 495 mmHg (660 mBar)
e. Adjust R100 (gain) until the display shows 495 mmHg
7-1