National Instruments 780152-01 Digital Multimeter

The National Instruments 780152-01, also known as the USB-4065, is a very accurate and adaptable six-and-a-half-digit digital multimeter. This device is excellent for measuring AC/DC voltage, AC/DC current, and resistance between two or four wires in addition to diode testing. Due to its low cost and wide range of features, it's a great option for OEMs, research facilities, or any other budget-conscious test and measurement application.

A wide range of DC system speed characteristics can be effectively handled by the 780152-01. The device provides a 10 per second function change rate and an auto range time of 200 ms for resistance and 200 ms for DC voltage and current. With a trigger delay of less than 1 μs and a maximum trigger rate of 2.5 kHz, the device guarantees quick and precise readings. With the exception of the 300 V and 3 A ranges, it can cover 105% of the range over. Its precision is enhanced by the fact that, at 23 °C, the DC voltage input bias current is usually less than 40 pA. Furthermore, for power-line frequencies ±0.1%, it has second-order DC noise rejection and an effective common-mode rejection ratio (CMRR) of > 150 dB.

With a maximum trigger rate of 2.5 kHz, the 780152-01 preserves the same rate of 10 function changes per second and a trigger latency of less than 1 μs for AC system speed characteristics. For AC measurements, the nominal input impedance is 10 MΩ in parallel with 200 pF, and the input method is AC coupling. It can manage up to 250 V for the maximum DC voltage component and 3 x 10^7 V-Hz for the maximum Voltz-Hertz product. When measuring AC at frequencies between DC and 60 Hz with a 1 kΩ resistance in the LO lead, the CMRR is 70 dB. For AC measurements, the overrange capability is likewise 105% of the range, with the exception of the 300 V and 3 A ranges.

For both input and output triggers, the 780152-01 offers a variety of options in terms of trigger characteristics. A minimum pulse width of 200 ns is required for both the Trigger and Sample Trigger input triggers, which are programmable by edge and sourced from the auxiliary connector (AUX I/O connector). Measurement Complete is indicated by output triggers, which have a programmable edge destination through the auxiliary connector. They provide a logic level of 3.3 V and a pulse width of 1 μs.