Oscilloscope Probe Selection
One of the most notorious questions asked when engineers and technicians need to make oscilloscope measurements is 'what probe should I use'? Oscilloscope probes at their most basic can be viewed as a transmission line for connecting a DUT (Device Under Test) for oscilloscope input. There is a host of different oscilloscope probes to choose from, and they all have applications where they perform best. Decided by the signal that materials are to measure you could possibly want a Passive, Active, Differential, Trimode, or Current probe. But for the factors like this discussion I wants to limit the conversation to voltage probes. A variety the key parameters that you should take into account when selecting an oscilloscope rental are the bandwidth (BW) or frequency, amplitude of the signal you're looking for to measure, and the impedance of the probe. Please keep in mind that the bandwidth of your oscilloscope probe will be limited by the bandwidth of the test equipment you select. Passive Probes Passive oscilloscope probes usually have the greatest dynamic range; some of them can be found with a selectable divider network for 1X, 10X and 100X attenuation places. Passive oscilloscope probes are primarily made of a coaxial cable while a resistor and capacitor carrier. The simple construction of the used oscilloscope make passive probes one of the cost-effective test equipment rentals on the market. There are no active components in the circuit, so there is magnetic water conditioner s to supply power towards the probes. The typical bandwidth of a passive probe is 600MHz, or not so much. However, there are some specialty passive probes with bandwidths in the Gigahertz range. Single-Ended Active Probes Active oscilloscope probes contain an active amplifier (typically a FET) and they've very low capacitance as well as high input impedance. Because of their low capacitance they can double with longer ground leads, and they have low DUT loading impact. Active FET probes would develop into a good choice if you've to measure low signal levels, or fast logic signals. These electronic equipment rentals can operate at much higher bandwidths than single ended passive probes with some as high as 6 GHz. Differential Probes A differential oscilloscope probe has two inputs; one positive (non-inverting), and one negative (inverting) input. The two input signals are fed into a differential amplifier that combines for a single differential signal to input into the oscilloscope. Just one of the primary benefits of a Differential probe is this has a high CMRR (Common Mode Rejection Ratio). The high CMRR is especially important when you are attempting to measure small signals that are riding on a large DC offsets. Differential probes can be found with bandwidths up to 20GHz. TriMode Probing TriMode oscilloscope probes are presently only offered by Tektronix. This probe allows you to make one connection to your DUT and, then you can certainly can measure Differential, Single ended, and common Mode measurements with one setup. TriMode probes can save both set up time by only having to make one connection for multiple measurements, too as money by only having to purchase one probe. These digital oscilloscopes were a good choice if you will want to measure multiple serial data compliance standards (HDMI, SATA, PCIe, etc.). Trimode probes come in various bandwidths up to 20GHz. Once experience determined the oscilloscope probing requirements, you'll need to plan your acquisition strategy. Should the project is short-term, an used oscilloscope or rental can be your best fluid. Oscilloscope rentals allow you to scale to project size and scope, minimize capital outlay and quickly replace a down printer. If your project is long-term, or repetitive in nature, a lease or purchase possibly be a better decision.