High-impedance scope probes are designed for the conventional 1 megohm oscilloscope, but the 1 megohm input impedance is only at low frequency; the input impedance is not a constant 1 megohm across the probe's bandwidth but rather decreases with frequency.
42.
The same basic measurement is read out in either conductivity units of microsiemens per centimeter ( �S / cm ), typical of the pharmaceutical and power industries or in resistivity units of megohm-centimeters ( Mohm " cm ) used in the microelectronics industries.
43.
Because the oscilloscope input has some parasitic capacitance in parallel with the 1 megohm resistance, the 9 megohm resistor must also be bypassed by a capacitor to prevent it from forming a severe RC low-pass filter with the'scope's parasitic capacitance.
44.
Because the oscilloscope input has some parasitic capacitance in parallel with the 1 megohm resistance, the 9 megohm resistor must also be bypassed by a capacitor to prevent it from forming a severe RC low-pass filter with the'scope's parasitic capacitance.
45.
A quality general-purpose electronics DMM is generally considered adequate for measurements at signal levels greater than one millivolt or one microampere, or below about 100 megohms; these values are far from the theoretical limits of sensitivity, and are of considerable interest in some circuit design situations.
46.
The result is a frequency compensated probe for modest frequencies that presents a load of about 10 megohms shunted by 12 pF . Although such a probe is an improvement, it does not work when the time scale shrinks to several cable transit times ( transit time is typically 5 ns ).
47.
Since resistors are specified and manufactured over a very large range of values, the derived units of milliohm ( 1 m? = 10 " 3 ? ), kilohm ( 1 k? = 10 3 ? ), and megohm ( 1 M? = 10 6 ? ) are also in common usage.
48.
It is connected to ground through a coiled retractable cable and 1 megohm per 250 V ) is added in the path to ground to protect the wearer from excessive currents; this typically takes the form of a 4 megohm resistor in the coiled cable ( or, more usually, a 2 megohm resistor at each end ).
49.
It is connected to ground through a coiled retractable cable and 1 megohm per 250 V ) is added in the path to ground to protect the wearer from excessive currents; this typically takes the form of a 4 megohm resistor in the coiled cable ( or, more usually, a 2 megohm resistor at each end ).
50.
It is connected to ground through a coiled retractable cable and 1 megohm per 250 V ) is added in the path to ground to protect the wearer from excessive currents; this typically takes the form of a 4 megohm resistor in the coiled cable ( or, more usually, a 2 megohm resistor at each end ).
