Vacuum pump plate (8 x 8 in.) is made of durable, chemically resistant HDPE (high-density polyethylene). Included with the vacuum plate is a gum rubber gasket. The gasket creates the vacuum tight seal between the vacuum bell jar and the vacuum pump plate without using messy, sticky vacuum grease.
A vacuum bleed valve regulator is built-into the vacuum plate for monitoring and regulating vacuum level. This regulator consists of a fine brass needle valve and a 2 in. OD dial vacuum gauge, 0 to 30 in. Hg. By opening and closing needle valve, user can adjust flow of air into vacuum pump and vary vacuum pressure in bell jar. Needle valve is also a gentle vacuum release at the end of an experiment.
Needle valve has a #10-32 female thread port (refer to photo of vacuum pump plate).
The dial vacuum gauge provides a quick and easy way to measure vacuum pressure in the bell jar. Vacuum pressure is any pressure below atmospheric pressure. The gauge displays the vacuum pressure in the bell jar from 0 in. Hg(atmospheric pressure) to 29.92 in. Hg(0.01% of atmosphere).
Includes Owner's Manual with instructions for use.
Benefits of a built-in bleed valve regulator with dial gauge include:
- Maintain specific vacuum pressure in bell jar to control processes such as vacuum degassing, vacuum encapsulation, product testing, and vacuum impregnation.
- Vacuum drying and outgassing electronic components.
- Vacuum infiltration of epoxy resin embedding agents.
- Repeating vacuum pressure in bell jar is essential for accurate and reproducible experimental results.
- Run controlled atmosphere experiment by backfilling gas into the bell jar chamber through #10-32 female threaded port on needle valve (refer to photo of vacuum pump plate).
- Demonstrate in real-time Boyle's law by showing how the volume of a balloon changes as vacuum pressure in bell jar is varied.
- Gentle vacuum drying of thermal, oxygen, and/or moisture-sensitive materials.
- Show sound needs a medium to transmit as the sound from a bell or buzzer fades as vacuum pressure decreases and sound returns as it is increased. Note at what vacuum pressure (29.7+ in. Hg) the sound source fades completely and becomes inaudible.
- Explain why water can be made to boil at room temperature. Note the boiling occurs when the vacuum pressure matches the vapor pressure of water (≈29 in. Hg) at room temperature (25°C). Raise vacuum pressure slightly and watch the boiling abruptly stop.
- Demo fluid transfer under low vacuum pressure from sealed flask thru U-shaped tube to a beaker in bell jar. Raise pressure in bell jar and watch as fluid flows back to sealed flask.
- Illustrate how the tiny air sacs (tiny balloons) making up a marshmallow, peep, or shaving cream inflate according to Boyle's law as vacuum pressure decreases. Note the vacuum pressure when the air sacs break causing the marshmallow, peep or shaving cream to deflate.
Additional features include:
An on/off chrome-plated brass vacuum ball valve on the plate is shutoff valve to vacuum pump. The brass hose barb on ball valve accepts 3/8 in. (10mm) ID flexible vacuum tubing.
The vacuum pump plate has four rubber bumper feet. For durability, the feet are held in place with bolts threaded into the plate. The feet raise the vacuum plate off the surface and provide cushioning and stability to the plate.
* Molded flint glass may show small imperfections. These imperfections, tiny spheres or surface blemishes, form during molding process and do not impact use in full vacuum applications.