This is a replacement tempered glass window for the Ideal Vacuum ISO-160 non-illuminated HALO View Window. It can be replaced in the field. Please see the HALO View Window User Manual, available in downloads for instructions on replacing the window media.

This replacement glass material is standard low-iron float glass. Surface quality and flatness is Q4 per ASTM 1036-06 and 1048-04. The low iron content of the glass results in it having a slight blueish tint. This economical glass is most commonly used for general, direct observation of roughing or high-vacuum chamber processes. This media is unsuitable for laser experiments below visible or beyond near-infrared (NIR) wavelengths.

We also offer replacement/upgrade windows made of fused silica. Our Corning HPFS 7980 fused silica HALO Viewports and replacement window panes are preferred for experiments where maximum optical clarity and transmissivity is required from Near Ultraviolet (NUV) to Near Infrared (NIR). The windows have nearly 100% transmissivity from 300 to 1000 nm.

Please see the graph below for the transmissivity curves of tempered glass and fused silica:

HALO Viewport replacement windows are available in ISO 63, 80, 100, 160, 200 and 250 sizes and are used in place of blank ISO flanges. Like other ISO fittings, these ISO flanged windows use either single or double claw clamps along with a centering ring fitted with an O-ring. Use double claw clamps on ISO-K to ISO-K connections. Use single claw clamps on ISO-K to ISO-F (bolted) connections. The recommended number and type of claw clamps and the centering ring required is shown in the table below:

Our ISO viewing windows employ an innovative, zero metal-to-glass contact design that holds the 3/8” thick window pane to a stainless steel mounting flange. This cushioned window mounting system ensures operator safety and is less prone to leakage than other viewport window configurations, even at high-vacuum pressures. Ideal Vacuum ISO HALO viewing windows are delivered fully assembled and use Viton O-rings and Teflon spacers. Bakeout temperatures to 150 °C are permissible.

NOTE: All viewing windows or ports are inherently fragile, should be handled carefully, and always inspected before use. Ideal Vacuum viewing windows are designed and rated for VACUUM ONLY and can be susceptible to thermal shock if exposed to rapid temperature changes (>10° C /min). If directing a laser beam through the window, make sure the laser’s wavelength can be reasonably transmitted through the window’s material. Illuminated HALO Viewports are not field serviceable. Please contact Ideal Vacuum if you need to replace the tempered glass or upgrade it to a fused silica window. Please download and read all the safety warnings in the Illuminated HALO Viewport Window User Manual.