ISO 2431 viscosity cup

ASTMaluminumstainless steel

Overview
The Rhopoint Flow Cups measure the viscosity of paints, inks, varnishes and similar fluids by recording orifice flow time. Results can be converted to kinematic viscosity (cSt) using a viscosity calculator.

Key features

• Orifice diameters available: 3 mm – 8 mm (0.12" – 0.31")
• Viscosity (kinematic) range covered: approximately 7 – 2000 cSt (depending on cup/orifice)
• Typical flow times: 30 – 100 seconds (dependent on orifice and fluid)
• Supplied with a certificate of conformity
• Sheen equivalents: Sheen 417/3, 417/4, 417/5, 417/6 & 417/8 equivalents

Construction & calibration
Manufactured from high grade aluminium alloy with stainless steel orifices. Flow cups can be supplied with UKAS / ISO 17025 certified standard oils to verify measurement performance and calibration.

How it works
Viscosity describes a fluid's resistance to flow (shear). The flow cup measures the time for a fluid to pass through a defined orifice; this flow time is used as a practical relative measurement and can be converted to centistokes (cSt).

Product range (summary)
Product / Order code / Orifice diameter / Viscosity range / Flow times
Flow Cups to BS EN ISO 2431, ASTM D5125 – RL-A-FC-ISO3 – 3 mm (0.12”) – 7 - 42 cSt – 30s - 100s
Flow Cups to BS EN ISO 2431, ASTM D5125 – RL-A-FC-ISO4 – 4 mm (0.16”) – 35 - 135 cSt – 30s - 100s
Flow Cups to BS EN ISO 2431, ASTM D5125 – RL-A-FC-ISO5 – 5 mm (0.20”) – 91 - 325 cSt – 30s - 100s
Flow Cups to BS EN ISO 2431, ASTM D5125 – RL-A-FC-ISO6 – 6 mm (0.24”) – 188 - 684 cSt – 30s - 100s
Flow Cups to BS EN ISO 2431, ASTM D5125 – RL-A-FC-ISO8 – 8 mm (0.31”) – 600 - 2000 cSt – 30s - 100s

Additional product notes
Orifices manufactured from stainless steel. Weight typically 200 - 300 g depending on model. Commodity code 9027 8091.

Technical specifications

• Standards: ISO 2431 and ASTM D5125
• Orifice diameters: 3 mm, 4 mm, 5 mm, 6 mm, 8 mm
• Viscosity ranges (examples by orifice): 3 mm: ~7–42 cSt; 4 mm: ~35–135 cSt; 5 mm: ~91–325 cSt; 6 mm: ~188–684 cSt; 8 mm: ~600–2000 cSt
• Flow time window: approximately 30–100 s (application dependent)
• Material: high grade aluminium alloy body; stainless steel orifices
• Weight: ~200–300 g (model dependent)
• Supplied with certificate of conformity; UKAS / ISO 17025 certified standard oils available for calibration verification
• Sheen equivalents: Sheen 417/3, 417/4, 417/5, 417/6 & 417/8
• Typical order codes / SKUs: RL-A-FC-ISO (product family) with specific SKUs per orifice (e.g. RL-A-FC-ISO3, RL-A-FC-ISO4, RL-A-FC-ISO5, RL-A-FC-ISO6, RL-A-FC-ISO8)