For example, RFD devices detect the radio signals emanating from a cellphone, while FMD devices detect the ferromagnetic components that are common within cellphones, and NLJD devices leverage the unique properties of semiconductors used in electronic products to detect cellphones.
Testing showed that the NLJD and FMD devices can detect cellphones in the on or off positions, which is an advantage; however, the operator must be in very close proximity to the phone (less than 8 inches).
After a 60-day use of all four devices following the formal testing, the officers overall preferred the RFD devices over the NLJD and FMD devices.
An ORION NLJD was tested by the GEO Group in Florida and Pennsylvania initially, and was able to detect and locate mobile phones and other electronic contraband successfully.
Although the ORION NLJD is not able to detect non-electronic contraband, other prison systems using the equipment have confirmed that other contraband such as drugs and weapons had been located when detecting mobile phones.