WE WILL RE-CALIBRATED THE UNIT BEFORE SHIPPING AND A NIST TRACEABLE CALIBRATION CERTIFICATE WILL BE PROVIDED.

Tektronix TDS640 Oscilloscope, Digital: 500MHz,2GSa/s,4ch (Stand alone) The Tektronix TDS640 oscilloscope is a graph-displaying device – it draws a graph of an electrical signal. In most applications, the graph shows how signals change over time: the vertical (Y) axis represents voltage and the horizontal (X) axis represents time. The intensity or brightness of the display is sometimes called the Z axis. The Tektronix TDS640 oscilloscope's simple graph can tell you many things about a signal, such as: the time and voltage values of a signal, the frequency of an oscillating signal, the “moving parts” of a circuit represented by the signal, the frequency with which a particular portion of the signal is occurring relative to, other portions, whether or not a malfunctioning component is distorting the signal, how much of a signal is direct current (DC) or alternating current (AC) and how much of the signal is noise and whether the noise is changing with time.

FEATURES: *** Bandwidth 500 MHz *** 4 Channels *** Sample rate is 2GHz *** Infinite and variable persistence selectable from 250 ms to 10 s *** Update rate is 100 waveforms per second (500 point waveforms with infinite persistance display selected) *** Other features include zoom, Main and Delayed time base. Trigger types include Edge (main and delayed), Pulse (main) and Logic (main). @@@ Sensitivity Channel 1-4: 1 mV to 10 V/div @@@ Vertical Resolution: 8 bits (256 levels over 10.24 vertical divisions) @@@ Analog Bandwidth Selections: 20 MHz, 100 MHz, @@@ full Input Coupling: AC, DC or GND @@@ Input Impedance Selections: 1 Mohm in parallel with 10 pF, or 50 ohm (AC and DC coupling) @@@ Time Bases: Main, Delayed.

It was just calibrated. Date Due 07/12/12. The unit is in great cosmetic condition. May have a small scratch here or there. There is 2 back feet missing. All buttons, knobs, and switches are good and intact. The serial # is B021017 . Works with 120 & 240 voltage. We always re-check the item before we ship it. This makes sure the item is working when it left my shop.