Which marking is NOT required on a separable electronic indicating device of an axle load scale manufactured in February 1989?

The correct choice indicates that the load cell verification interval marking is not a requirement on a separable electronic indicating device of an axle load scale manufactured in February 1989. During that time, regulations may not have mandated the verification interval as part of the required markings for such devices. This specific requirement can vary based on the rules in effect at the time of manufacture and may have been included in later guidelines.

In contrast, the manufacturer name, calibration date, and model number tend to be essential for identification, traceability, and ensuring that the device conforms to appropriate standards. These elements help users and regulatory bodies verify the credibility of the device and ensure that it has been properly calibrated and is functioning as intended.