U-GAUGE OIL MANOMETER*
OIL FILL & SCALE PLACEMENT INSTRUCTIONS
(*Pronounced ma-nom-eter, not man-o-meter)

AMOUNT OF OIL
There is no set amount of oil that has to be put into the U-gauge. But it needs to be enough so that if a neon unit is filled to 20mm pressure the oil in the U-gauge does not go past the bottom of the U-tube, which would cause the fill gas (or air) to bubble up the right side of the gauge. If this happens it does not cause any permanent damage, but will delay accurate readings until the oil drains down the tube and settles again.

ATTACH SCALE
Clip the scale onto the right side of the U-gauge board. Adjust the scale so the top of it is about even with the top of the 9mm tube on the right side of the gauge, where it flares out into the bottom part of the stopcock. This does not have to be an exact placement.

OIL FILL
Unscrew and remove the stopcock plug from the top of the U-gauge. Stand it up on the end of the black control knob so it doesn't lie on the table and get dirt on the O-rings. Using an eyedropper, extract some oil from the bottle. Carefully insert the tip of the eyedropper into the stopcock barrel and past the stopcock "seat" (where the tip O-ring seals). Gently squirt the oil into the tube. Repeat as necessary until the oil is one or two millimeters below the zero mark on the scale. Wait 10-15 minutes for the oil to drain down the tube and settle. Fill the gauge the rest of the way to the zero mark by adding a few drops of oil at a time. Slightly under filling or over filling is not a concern as the scale is easily adjusted. Once the oil is in, adjust the scale so the zero mark is exactly aligned with the top of the fluid level. Wipe any oil out of the stopcock barrel with an acetone-wetted piece of lint free paper towel (such as Bounty) wrapped around a fire polished piece of tubulation. Replace the stopcock plug but leave the stopcock open.

FIRST USE
SLOWLY open the main stopcock to apply vacuum to the manifold. The oil may foam up considerably at first. If this happens, immediately close the main stopcock until the oil stops foaming. If the main stopcock is opened too quickly the oil can foam up over the top of the left side of the gauge and down into the manifold. So go slowly! Open and close the main stopcock a little at a time until full vacuum is applied. Once the oil is done foaming and outgassing you can open and close the main and air vent stopcocks as quickly as you want without the oil foaming again.

DAILY USE
Follow the instructions in our RECOMMENDED BOMBARDING PROCEDURE for step-by-step instructions on how to use a U-gauge manometer to monitor bombarding pressure and measure fill pressure.

SVP Neon Equipment
(Silica Vacuum Products)
113 Leventis Drive, Suite A
Columbia, South Carolina 29209
Ph. (803) 783-1165
www.svpneon.com