Graduation Markings: Temperature Range -40°C to +300°C

Component Specifications

Definition

Graduation markings are calibrated reference lines, numbers, or symbols applied to the transparent surface of sight glasses or level indicators. These markings create a visual measurement scale that allows operators to determine the exact fill level, volume percentage, or material height within tanks, reactors, boilers, and other industrial containers without direct physical contact with the contents.

Working Principle

Graduation markings work by providing a fixed reference scale against which the liquid or material interface can be visually aligned. When light passes through the sight glass, the contrast between the markings and the liquid level creates a clear reading point. The markings are precisely positioned according to volumetric calculations or linear measurements corresponding to specific fill percentages or quantities.

Materials

Stainless steel (304, 316), borosilicate glass, tempered glass, polycarbonate, acrylic, ceramic enamel, vitreous enamel, epoxy-based inks, laser-etched surfaces

Technical Parameters

Parameter	Typical range	Notes & selection driver
Durability	Abrasion resistance >500 cycles (Taber test)
Line Width	0.1mm to 0.5mm
Resolution	1mm, 5mm, 10mm increments or percentage-based (1%, 5%, 10%)
Marking Depth	0.01mm to 0.1mm (for etched markings)
Contrast Ratio	Minimum 70:1 for legibility
Scale Accuracy	±0.5% to ±2% of full scale
Pressure Rating	Up to 150 psi (standard)
Temperature Range	-40°C to +300°C

Ranges are indicative industry figures for RFQ preparation, not a supplier commitment. Confirm every value and standard with the legal manufacturer before ordering.

Standards

ISO 4787, DIN 7079, ASME B40.100, ISO 6708

Parent Products

This component is used in the following industrial products

Sight Glass/Level Indicator

A transparent window or gauge that allows visual monitoring of coolant level within a reservoir.

View Product Details

Engineering Analysis

Risks & Mitigation

Misreading due to parallax error
Fading or wearing of markings over time
Chemical attack on marking materials
Incorrect calibration leading to measurement errors
Glass breakage exposing sharp edges

FMEA Triads

Trigger: Chemical corrosion from aggressive process fluids
Failure: Graduation markings become illegible
Mitigation: Use chemically resistant marking materials (ceramic inks, laser etching), implement protective coatings, establish regular inspection schedules

Trigger: Mechanical abrasion from cleaning procedures
Failure: Graduation markings wear off
Mitigation: Specify abrasion-resistant materials, provide proper cleaning instructions, use protective covers when not in use

Trigger: Improper installation alignment
Failure: Measurement inaccuracies due to skewed scale
Mitigation: Include alignment guides during installation, verify with spirit levels, provide installation training

Industrial Ecosystem

Compatible With

Typical Suppliers & Equivalents

Compliance & Inspection

Tolerance

±1% of indicated value for standard applications, ±0.5% for precision applications

Test Method

Visual inspection per ISO 2859 sampling, contrast measurement with spectrophotometer, durability testing with Taber abrasion tester, chemical resistance testing with relevant process fluids

Procurement Evaluation Criteria

A practical evidence checklist for RFQ preparation and supplier evaluation.

Technical documentation

Request current drawings, revision history, and a signed specification sheet.

Manufacturing capability

Verify equipment lists, process limits, capacity, and representative production evidence.

Inspection readiness

Confirm test methods, calibrated equipment, sampling plans, and traceable reports.

Supplier transparency

Check the legal entity, factory address, ownership, certifications, and direct contacts.

CNFX does not score or rank suppliers. Buyers must verify all claims and documents with the legal manufacturer before ordering.

Manufacturers of Graduation Markings

Manufacturer profiles associated with Graduation Markings.

Sourcing Graduation Markings from China?

Tell us your specification and target quantity — we will match it against manufacturer records and come back with the factories that fit.

Request manufacturers We manufacture this

Manufacturer listings support early research and capability understanding. They are not certification, ranking, or transaction guarantees.

Compiled and source-reviewed by the CNFX editorial team. Each manufacturer above links to the page on that company's own website where the product is listed, with the date we checked it. How we source and review

Related Components

Upper Tool (Punch)

Upper Tool (Punch) is the active forming component in metal plate bending machines that applies precise downward force to create bends in sheet metal.

Main Frame

The main frame is the primary structural component of a hydraulic press, providing rigidity and stability to withstand high compressive forces during metal forming operations.

Shaft Bearing

Precision component supporting rotating shafts in vibration motors to reduce friction and maintain alignment.

Seal Groove

Precision-machined groove in aluminum bearing housings designed to accommodate sealing elements for fluid containment and contamination prevention.

Frequently Asked Questions

What are the main types of graduation marking methods?

The three primary methods are: 1) Laser etching for permanent, chemical-resistant marks on glass and metal, 2) Screen printing using ceramic or epoxy inks for high visibility, and 3) Mechanical engraving for deep, durable marks on metal surfaces.

How are graduation markings calibrated for different tank shapes?

Markings are calibrated using volumetric calculations based on tank geometry (cylindrical, rectangular, spherical). For non-linear relationships between height and volume, markings may be spaced unevenly or include conversion charts. Computer-aided design ensures accurate positioning relative to actual content volume.

What maintenance do graduation markings require?

Regular cleaning with compatible solvents to maintain visibility, inspection for wear or fading, and verification against master gauges during calibration cycles. Avoid abrasive cleaners that could damage markings.

Data Basis

Editorial classification, named public sources where available, and source-reviewed manufacturer records. See the editorial policy.

Preliminary Technical Classification

This page supports structured research, RFQ preparation, and supplier evaluation. It does not replace buyer-led supplier qualification, standards review, or technical approval.

Graduation Markings