Celota enote lahko vključuje tudi avtomatske naprave, obtočne ventile, omejilnike pretoka itd. pod pogojem, da je vsak preskusni krog med vodomeri, ki jih overjamo, in kontrolnimi posodami jasno definiran in da je možno kadar koli preveriti njegovo notranjo absorpcijo tlaka.
The complete unit may include automatic devices, by-pass valves, flow-restrictors, etc., provided that each test circuit between the meters to be verified and the control tanks is clearly defined and that it is possible to verify at any time its internal pressure absorption.