A tingling sensation may be noticed when connecting devices to Dell laptop computers or printers and touching exposed metal parts of the devices being connected or the parent device. This tingling sensation can occur any time the AC adapter is connected and the user touches any exposed metal surface on the computer, the printer, the PDA, etc. This may lead to the conclusion that the device is unsafe. The electric current on all Dell products have been measured and proven to be well within the safety limits per safety standards - IEC950, EN60950, UL1950, etc., even with an input voltage of 240 Volts. The voltage (tingling sensation) does NOT present any risk of injury to the user. It is recommended to unplug the AC adapter from the parent device before attaching any cables or accessories, as this reduces the possibility of experiencing the tingling sensation.

	Note:
	Connecting multiple devices that use two-pronged power plugs increases electrical potential between exposed metal parts, thus increasing the potential of feeling a tingling sensation.

The voltage potential between exposed metal parts of the device and earth ground can be observed using various voltage measuring devices:

• It is possible to measure a voltage potential between 0 and 100 Volts or possibly higher.
• If a high impedance-measuring device (i.e., oscilloscope or digital voltmeter) is used, the voltage can be measured as high as 70 Volts or higher.
• If a low impedance-measuring device (analog voltmeter) is used, the measured voltage should be 30 Volts or lower.

The lowering of the voltage can be demonstrated by using a high impedance-measuring device and then touching the metal back plate of the computer; the voltage will drop, due to the lower impedance of the human body.