Portable Viscometer 321

321 Sensor- Image (HR)

Unique viscometer for in-tank blending and reaction monitoring

The model SPC/L 321 is an in-tank process viscometer that is installed in a tank of vessel to provide continuous temperature and viscosity tracking. Our technology is based on a simple and reliable electromagnetic concept. Two coils move a piston back and forth magnetically at a constant force. Proprietary circuitry analyzes the piston’s two-way travel time to measure absolute viscosity.

A deflector, positioned over the piston, moves fluid into the measurement chamber. This feature, coupled with the constant piston motion, keeps the sample fresh and mechanically scrubs the chamber. A built-in temperature detector (RTD) senses actual temperature in the measurement chamber.

The Model SPC/L321 viscometer can be immersed directly into a blend tank or a vessel. The “In-Tank” sensor provides continuous, accurate measurements of mixing and blending viscosities, as well as reaction tracking.

Measurements can be made in 13 different viscosity ranges within an overall span of 0.2 to 20,000 cP or the equivalent cSt. Maximum flow rate over the sensor head is 10 ft/sec (3 m/sec).

*NOTE: ALL ATEX SENSORS ARE SPL ONLY (L = hard wired, C = connector).

Key Features:

• For blend tanks and vessels  • Accurate and reliable  • Customer specified stem lengths  • One moving part, no wear points  • All wetted parts 316L stainless steel

Correlates with ASTM D445.


• TIIS Approved IIBT3 #TC15402
• Approved for Class 1, Div. 1, Group C & D
• Approved for EEx d IIC T2, -20C<Tamb<190C


Inserts into a blend tank or vessel



Viscosity 0.2 to 20,000 centipoise (cP)
Piston Ranges 0.2-2cP, 0.25-5cP, 0.5-10cP, 1-20cP,
2.5-50cP, 5-100cP, 10-200cP, 25-500cP,
50-1,000cP, 100-2,000cP, 250-5,000cP,
500-10,000cP, 1,000-20,000cP
Viscosity Accuracy ± 1.0% of full scale with VISCOpro 2000
Repeatability ± 0.8% of Reading
Temperature Sensor 4 wire internal Platinum RTD
Wetted Materials 316L and 430 Stainless Steel
Maximum Particle Size 25-360 microns (Range Dependent)
Max Ambient Temperature 375°F (190°C)
Max Operating Pressure 1,000 psi (70.3 bar)
Standard Cable Length 15 feet (4.57 meters)
Power Requires VISCOpro electronics