Understanding Vacuum

At sea level, the earth's atmosphere exerts a standard pressure upon us of 14.7 pounds per square inch absolute (PSIA), or 29.92" of mercury (Hg), or 760 mm of mercury (Torr). All of these values refer to "standard atmosphere" which is measured at sea level.

Vacuum is a term used to describe an area, zone, or compartment containing less pressure than atmospheric pressure.

Vacuum is measured in inches of mercury (Hg) in the United States. There are two different scales to measure vacuum.

One scale is referred to as "inches of mercury gauge vacuum" ("HgV), where the measuring range starts at 0 inches of mercury (atmospheric pressure) and goes up to 29.92 inches of mercury, known as perfect vacuum (not achievable on Earth).

The alternative scale is "inches of mercury absolute vacuum" ("HgA), which reverses the "HgV scale, having it instead read 29.92 inches of mercury at atmospheric pressure and 0 inches of mercury at perfect vacuum.

Here's an example of the relationship between inches of mercury gauge and inches of mercury absolute:

24 inches of Hg gauge = 5.92 inches of mercury absolute.
Calculation: 29.92 - 24 = 5.92

It is very important to  determine what scale you are using, meaning gauge or absolute. A misunderstanding can result in large errors.

The unit "Torr" is used when working in higher vacuum ranges (low absolute pressure). 1 Torr equals 1 millimeter (mm) of mercury in absolute pressure.

Considering one linear inch equals 25.4 mm, and atmospheric pressure (at sea level) is 29.92 inches of mercury, then using the equation 29.92 inches x 25.4 mm = 760 Torr. 760 Torr is 0 vacuum, while 0 Torr is perfect vacuum.

BCE is a leading manufacturer of electrical, fiber optic, and tubing feedthroughs for use in vacuum applications. Visit https://bcemfg.com or call (510) 274-1990 to learn more.

Vacuum Feedthroughs the Way You Want Them

Equipment manufacturers and scientific researchers are continually challenged with supplying power, fiber-optic, control, and monitoring cables into sealed vacuum vessels. Whether due to space restrictions, special geometries, or number and type of conductors, standard glass-to-metal or ceramic feedthroughs never quite fit the bill. Unfortunately, because of limited options, many designers are forced to compromise and go for an off-the-shelf solution.

Until now. 

BCE designs, engineers, and manufacturers feedthroughs that can handle custom shapes, tight angles, curves, shielded wire and still provide a tight seal.

Why You Need to Consider BCE:

• Feedthroughs Designed to Your Specifications
• 24 Hour Turnaround on Custom Drawings & Quotations
• Custom Feedthroughs Ship in 2 Weeks

Call today. 510-274-1990

Custom Electrical, Pneumatic, and Optical Feedthroughs

Equipment manufacturers and scientific researchers are continually challenged with supplying power, fiber-optic, control, and monitoring cables into (and out of) sealed vacuum vessels. Whether due to space restrictions, special geometries, or number and type of conductors, standard glass-to-metal or ceramic feedthroughs never quite fit the bill. Unfortunately, because of limited options, many designers are forced to compromise and go for an off-the-shelf solution.

You don't have to fit a square peg in a round hole anymore. Choose BCE custom feedthroughs for your next design.

http://www.belilove.com/feedthrough

(510) 274-1990

Fiber Optic Cable Epoxy Vacuum Feedthrough

Here is a short video outlining the design of a fiber optic vacuum feedthrough assembly.

Epoxy compounds now rival glass and ceramic in performance. BCE is at the forefront of this development and leverages modern epoxy's unique properties to solve your feedthrough challenges.

BCE's sixty years of high-tech design experience in semiconductor equipment, medical equipment and R&D yields innovative vacuum feedthrough solutions.

Call Today (510) 274-1990 or visit http:// www.belilove.com/feedthrough