At any time the judge of the juvenile court may, and upon the request of the county board of supervisors shall, require the probation officer to examine into and report to the court upon the qualifications and management of any society, association, or corporation, other than a state institution, which applies for or receives custody of any ward or dependent child of the juvenile court. No probation officer, however, shall, under authority of this section, enter any institution without its consent. If such consent is refused, commitments to that institution shall not be made.