C.5.1.3 Bridge Rods with Relocating Device

The 20-mm rods described in Section C.5.1 can be supplied in 1-m sections to a maximum practical length of 7-m with sequentially number graduations. The OSS B1 and OTT C31 can be directly attached to this rod. Other meters may be attached using a variety of available clamping adapters; however, changing the placement of the meter to obtain the correct depth of observation can be awkward and exposes the meter to damage at sites where a long rod is required. To avoid these problems a relocating device should be employed (Figure C-28).

The manufacturers of the OTT and OSS current meters provide an assembly that gives top setting capability to a 20-mm rod of any length. The assembly consists of two or more 1-m sections of tube with locking connectors that fit over the 20-mm rod, providing an attachment point for the current meters. The use of the relocating device offers the advantage that the current meter can be positioned along the vertical in the measuring point without taking the equipment out of the water. The device, designed primarily for use with the B1, C31, and C5 meters, can also accommodate small current meters such as the PC1 and the C2, as well as Price meters. Adapters are required.

Note: A company in Penticton, BC manufactures (to order) a similar complete assembly with identical capability.

Figure C-28. Relocating device.