The Seametrics MJN Series Pulse Water Meters use the multi-jet principle, which has been an internationally-accepted standard for many years. This type of meter is known for its wide range, simplicity, and accuracy in low quality water. The MJN Series are certified to NSF/ANSI 61. The impeller is centered in a ring of jets, with inlet jets on one level and outlet jets on another. A gear train drives the register totalizer dials. For pulse output, one of the pointers is replaced by a magnet, which is detected by an encapsulated sensor attached to the outside of the lens.

Changing the pulse rate requires no special tools and can be done in the field. Mechanically, all MJN-Series meters are the same. The MJN Series has a brass body and is available in 3/4", 1", 1½" and 2" versions. The MJNE meters use a solid-state, long-lasting Hall-effect sensor, which requires power. It is suited for use with Seametrics controls and metering pumps that have sensor power. The MJNR meters use a two-wire reed switch providing a dry contact closure without requiring power. The MJNT meters totalize only and do not have a sensor.

Flow ranges vary by size from 0.25-20 GPM (3/4in) up to 2-160 GPM (2in), all with ±1.5% of reading accuracy. Maximum operating pressure is 150 psi with temperature limit of 105°F (40°C). The dry top multi-jet design ensures reliable operation even in low quality water applications.