Which type of extinguisher does not require a verification of service collar installed?

The option referring to new extinguishers needing charge in the field is accurate because these extinguishers are typically shipped from the manufacturer ready for use, but they may require charging or minor adjustments upon installation. Since they are new, they have not undergone any prior service that necessitates a verification of a service collar.

Service collars are used to indicate that an extinguisher has been recently serviced or inspected. For new extinguishers, this step is not required immediately upon their deployment because they come with their necessary components intact and certified from the factory.

In contrast, refurbished extinguishers would have undergone previous service and thus would require verification of their service collar. Portable extinguishers, being a category that generally requires regular inspections, are also obligated to have their service collars verified. CO2 extinguishers, while specific in their use and maintenance, still fall under the general regulations requiring verification of service for safety compliance.

Overall, the distinction for new extinguishers needing a charge lies in their fresh status and not having previous service records, making a service collar verification unnecessary at the time of installation.