Device Checks with Representative from Device Company Present

Our physician office has conflicting ways of billing device checks when a representative is present from the device company.

We are disagreeing that a 26 modifier needs to be appended to all charges when a representative is present no matter who performs the check and who owns the equipment.

We own the equipment and the techs are employed by the provider office; in this instance would we add the 26 modifier?

If the representative uses equipment of the company they are from a 26 modifier would then be added correct?

Thanks.

Device Checks with Representative from Device Company Present