Do the digital voltmeter and ammeter on the precision car need calibration?

Generally speaking, digital display meters do not need calibration. Of course, if there are high requirements for the accuracy of production and instruments, they can be calibrated regularly.

If the instrument is calibrated, it can be returned to the manufacturer for calibration, because manufacturers generally have calibrators for calibration.

You can also send the instrument to the measurement and monitoring center for calibration, but it is generally charged, and the specific amount is unknown.

You can ask specifically.