Calibrated On-Screen Edge Ruler & Fitting Sizer
Optimized with a vertical right-edge scale. Hold your phone upright and align physical AC copper tubing, barrier hoses, fittings, or O-rings directly against your device's right glass edge.
Calibrated On-Screen Edge Ruler & Fitting Sizer
Calibrated edge scale for physical measurement. Select Right, Left, Top, or Bottom edge, calibrate with a standard Credit Card (with auto-rotating scale), or open Full-Screen Bezel Mode.
Measurement Best Practices
Frequently Asked Questions: Edge Ruler & AC Sizing
Practical guidance on screen calibration, phone edge measurement, hose dash sizes, and O-ring verification.
Why is the on-screen edge ruler placed vertically along the right side of the phone?▼
Phones are much taller vertically (5.5 to 6.7 inches) than they are wide. Aligning the ruler vertically along the right glass edge allows mechanics and technicians to hold the phone naturally in their hand and press AC copper lines, rubber barrier hoses, or fittings directly against the physical right bezel without obstructive screen borders.
How do I calibrate the screen ruler to achieve 100% true physical size?▼
Select Method 3 (Credit Card Calibration). All standard credit, debit, and driver license cards worldwide follow the ISO/IEC 7810 ID-1 standard of exactly 85.60 mm (3.370 inches) in width. Place your physical card over the on-screen card outline and drag the slider until the outline matches your card perfectly. Click 'Save & Lock Calibration' to store your calibrated PPI in local browser storage.
What are the standard outer diameter (OD) sizes for automotive AC hoses?▼
Automotive R134a barrier hoses follow standard SAE J2064 dash sizes: #6 (Liquid Line) has an OD of approximately 5/16" (8 mm ID / 14.7 mm OD); #8 (Discharge Line) is 13/32" (10 mm ID / 17.5 mm OD); #10 (Suction Line) is 1/2" (13 mm ID / 21.0 mm OD); and #12 (Rear AC or Heavy Duty) is 5/8" (16 mm ID / 24.5 mm OD). Use the quick preset buttons on the ruler to verify your line size.
How do I accurately size an automotive AC O-ring with this ruler?▼
Place the rubber O-ring flat against your screen. Measure both the Outer Diameter (OD) and cross-sectional thickness. Most automotive R134a systems use green or black HNBR O-rings: #6 (0.43" / 11mm OD), #8 (0.55" / 14mm OD), and #10 (0.68" / 17.5mm OD). Always verify that the replacement O-ring is snug in the fitting groove without stretching.
Does browser zoom affect the accuracy of the ruler?▼
Yes. For accurate physical measurements, your browser zoom must be set to 100% (press Ctrl+0 on Windows or Cmd+0 on Mac). If you have customized your operating system display scaling (e.g. 125% or 150% in Windows display settings), use Method 3 (Credit Card) to calibrate, which automatically compensates for OS scaling factors.
How do I switch the edge ruler between metric millimeters and fractional inches?▼
Click the 'mm / cm' or 'Inches' toggle buttons at the top of the ruler tool. In metric mode, major numbered tick marks denote centimeters with 1mm increments. In imperial mode, ticks show 1/16-inch increments, with major labels at full inches. You can also click the quick preset line buttons (#6, #8, #10, #12) to automatically position the measurement guide.
What is the difference between Reduced Barrier and Standard Barrier AC hoses?▼
Both hose types have the same inside diameter (ID) to flow identical volumes of R134a, but Reduced Barrier hoses (thin wall) have a significantly smaller outer diameter (OD) and tighter bend radius, making routing through compact modern engine bays easier. For example, a #8 standard barrier hose is 17.5mm OD, whereas a #8 reduced barrier hose is only 14.5mm OD. Always match your crimp ferrules and fittings to the exact hose OD measured on this ruler.