Reflex Level Gauge Glass

What Is a Reflex Level Gauge Glass?

A Reflex Level Gauge Glass is a type of sight glass designed to provide a clear visual indication of the liquid level inside a sealed vessel. Unlike transparent level gauges, reflex gauges use prismatic glass to enhance the contrast between liquid and vapor phases, eliminating the need for auxiliary lighting.

Reflex Level Gauge Glasses are essential tools in industrial settings where accurate liquid level monitoring is critical. Widely used in boilers, chemical tanks, and pressure vessels, these devices allow direct visual observation of liquid levels using a specially engineered optical glass. In this article, we explore how reflex gauges work, their key advantages, applications, selection criteria, and best practices for installation and maintenance.

Common Applications of Reflex Level Gauges

Steam boiler systems: Reflex level gauge glasses are widely used in steam boilers due to their resistance to high temperature and pressure. They provide reliable level readings even under extreme conditions.
Chemical and petrochemical plants: Their compatibility with aggressive fluids makes them ideal for monitoring tanks that store acids, solvents, or hydrocarbons.
Water treatment facilities: In remote or automated systems, reflex gauges offer dependable level monitoring without needing electrical connections or sensors.

Benefits of Reflex Level Glass

Reflex level gauges are highly favored across industries for their durability and efficiency:

Clear level indication without backlighting
Robust and compact design
Low maintenance costs
High pressure and temperature resistance
No moving parts or external power required

These advantages make reflex gauges an ideal choice for straightforward, reliable liquid level monitoring.

Tempered Borosilicate Level

Sight Glasses DIN7081 — Reflex

Reflex level gauge glasses made out of borosilicate are a critical tool in various industrial applications, offering a simple yet effective method to visually monitor the liquid level within tanks and vessels.

These devices utilize a series of prisms embedded in the glass that reflect light differently depending on whether they are in contact with a liquid or gas. When the liquid level is present, the prisms in contact with the liquid allow light to pass through, making the liquid level appear dark against a silvery background. Conversely, in areas where no liquid is present, the prisms reflect light, making these sections appear bright.

This clear visual contrast provides an immediate and accurate indication of the fluid level, facilitating safe and efficient process management in industries such as chemical manufacturing, petroleum refining, and power generation, where precise level measurement is crucial for operational safety and efficiency.

More details

Tempered borosilicate level sight glasses DIN7081 reflex

Crystal length l by size

THK b	RD r	2	3	4	5	6	7	8m	9	10	11
30 mm	15 mm	140 mm	165 mm	190 mm	220 mm	250 mm	280 mm	320 mm	340 mm	370 mm	400 mm
34 mm	17 mm	5-1/2"	6-1/2"	7-1/2"	8-5/8"	9-7/8"	11"	12-5/8"	13-3/8"	370 mm	400 mm

Chemical properties

Property	Specification
Hydrolytic resistance	HGB 1 (ISO 719)
Acid resistance	CLASS S1 (ISO 1776)
Alkaline resistance	CLASS A2 (ISO 695)
SiO₂	Min 80% content
B₂O₃	Min 13% content
Na₂O + K₂O	Min 4.5% content