Spray the port and metering rod
until they're clean (wear eye protection and gloves).
After the sheet is pre-calendered, it is film-coated in a metering rod
BASF Plastics' Ultraform acetal copolymer is used to mold the ball valve and two components--the metering rod
and sensor disk.
The design in the patented Model 1230 design divides the valves into two parts: a wetted module that contains the metering chamber, and a power head module that pneumatically drives the metering rod
. The Model 1230 valve offers the same reliable volumetric shot consistency of other valves from the company but offers a number of additional benefits.
Hubble's mirror makers used laser light and the precision measuring tool -- called a metering rod
-- to determine how far apart to space two components of the grinding guide, a device known as the reflective null corrector (SN: 7/21/90, p.39).
The components are then forced by metering rods
directly into a disposable static mixer.
Depending on the metering rods
selected, the valve is capable of dispensing 5 cc of material down to 0.0005 cc.
The Direct Mount Posimeter system from Liquid Control Corp., North Canton, Ohio, uses positive-displacement metering rods
and balanced inlet/outlet spool valves, which are said to provide [+ or -]1% ratio and shot-size control.