Probe (Source) Leakage Current Test - GE Voluson E Series Service Manual

10.6.9 Probe (Source) Leakage Current Test

Warning
Do not use the probe if the insulating material has been punctured or otherwise compromised. Integrity of the
insulation material and patient safety can be verified by safety testing according to IEC60601-1.
10.6.9.1 Definition
This test measures the current that would flow to ground from any of the probes through a patient who is
being scanned and becomes grounded by touching some other grounded surface.
Each probe will have some amount of leakage, dependent on its design. Small variations in probe leakage
Note
currents are normal from probe to probe. Other variations will result from differences in line voltage and test
lead placement. It is abnormal if no leakage current is measured. If no leakage current is detected, check the
configuration of the test equipment.
10.6.9.2 Generic Procedure on Probe Leakage Current
The most common method of measuring probe leakage is to partly immerse the probe into a saline bath
while the probe is connected to the ultrasound system and active. This method measures the actual leakage
current resulting from the probe RF drive.
Measurements should be made under the test conditions specified in:
•
Table 10-10 on page 10-11
For each combination, the probe must be active to find the worst case condition.
Record all data and keep the record of the results with other hard copies of maintenance data.
Saline water pod should be insulated from floor and earth ground.
Note
The Saline solution is a mixture of water and salt. The salt adds free ions to the water, making it conductive.
Normal saline solution is 0.9% salt and 99.1% water. If ready-mixed saline solution is not available, a mixture
of 1 quart or 1 liter water with 9 or more grams of table salt, mixed thoroughly, will substitute.
1 Ultrasound System
2 Tester
3 Neutral Switch
Each probe will have some amount of leakage, dependent on its design. Small variations in probe leakage
Note
currents are normal from probe to probe. Other variations will result from differences in line voltage and test
lead placement. It is abnormal if no leakage current is measured. If no leakage current is detected, check the
configuration of the test equipment.
Voluson E-Series Service Manual
5539550APB Revision 6
, as applicable for every probe.
Figure 10-4 Set Up for Probe Leakage Current
4 Ground Switch
5 Polarity Reversing Switch
6 Meter
Care and Maintenance
7 Isolator
8 Ultrasound Probe
9 Saline Probe
10-19