There are a many different types of test probes that are used in various applications throughout the electronics industry. Electronic Toolbox sells test probes that are matched to particular models of Handheld Oscilloscopes and Digital Multimeters for many major brands. It’s important to match a probe's specifications to meet the specific needs of each models capabilities before using them together. Also having a good knowledge of input capacitance, circuit loading, frequency response and bandwidth can also be important factors when choosing test probes. These factors may make the difference in making the proper diagnosis when troubleshooting some electronic equipment. When choosing your test probes you should consider some of these essential requirements. First, they must be able to connect easily to the circuit and your test equipment; second, they must not load the signal source; third, they must be immune to noise and they must be able to pass on the signal accurately. When using a test probe, there will be some loading because the oscilloscope or digital multimeter will need to draw some sensing current. Again this is a factor that needs to be taken into consideration when purchasing test probes for your Handheld Oscilloscopes or Digital Multimeter. There may also be some distortion because of small values of capacitance and resistance. In order to help minimize these effects you should consider the following: Use standard test probe sets, keeping cable lengths short. Also using test probes that are the correct size together with an adapter that matches the device under testing can be of great help as well. Of course the ideal test probes would have an infinite input resistance and noise rejection, and zero input capacitance. Unfortunately these ideal conditions will never exist, so you will need to compensate for those factors. Test probes can be categorized three ways: General-purpose passive test probes, active test probes for high-frequency measurements, and differential probes that will eliminate undesired common mode signals. General-purpose probes, also known as 1X probes were designed to be an easy connection to a circuit being trouble shooted, to a digital multimeter or oscilloscope input. Active probes use devices such as FET and MOSFET transistors to increase the input impedance and reduce input capacitance below one Pico fared. This helps in preventing signal loss. These probes are used for very high-impedance type electronic circuits in order to avoid overloading them, and for extremely high frequency measurements into the GHz range. Differential probes are used to measure two signals, an example of this would be signals in a phone or a power and disk-read circuit. For more information on the test probes we offer on our web site please call us at 800-872-9456. We will be happy to assist you in any way we can.



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Mark Boehm