Ultrasound Technologies PD1 series, Руководство по обслуживанию

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Ultrasound Technologies Ltd
4.0
9
Test and Calibration
4.1
6 9
Introduction
The following sections detail tests to ensure that the unit is operating within specification.
These tests may be performed in whole or part, however, if any repairs are carried out to the
power supply circuits then it is recommended that the whole test / calibration procedure is
undertaken.
4.2
7 0
Performance Checks
The following procedure is intended to provide a means of determining the functional status of
the unit. It should be included as part of a preventative maintenance plan and should be
performed on a regular basis at least once a year.
Ensure that a full capacity alkaline cell is fitted.
Switch the unit ON and increase the volume to maximum. The battery low indicator will flash
ON momentarily and then extinguish.
Place the transducer with ultrasound gel on the palm of the hand over the radial artery, a
clear pulse will be heard.
Check the unit for signs of damage, particularly the transducer cable near the point of entry to
the unit and transducer body.
4.3
7 1
Equipment
Oscilloscope 2 channel 50 MHz bandwidth minimum resolution 5mV/cm
DC Power Supply 0 – 30VDC @1A
Digital Multimeter 4 Digit measuring 1mV, 1mA, 0.1ohm
Frequency Counter 0 - 10MHz resolution at 2MHz 1KHz.
Signal Generator 10Hz to 10MHz 1mV to 10V Sinewave
4.4
7 2
Audio Unit
Set the power supply to 9VDC output and connect to battery fling leads.
Switch ON the power supply.
Switch the board under test ON by shorting pins 1 and 2 of connector J1.
Check the battery low LED flashes momentarily.
Check the current being drawn by the board under test is less than 50ma.
Using the DVM, measure the DC voltage at the Drain of Q2 (junction of C8 & C11) this will be
between 8.80 and 8.60 V DC.
Carefully decrease the power supply output, check and record the voltage reading at which
point the Battery low LED illuminates permanently. This will be between 7.0 and 7.5 V DC
©Ultrasound Technologies Ltd Page 13 of 32
PD1 / FT120 service manual Issue 3 January 2007