In a rotational viscometer set to 600 rpm, a dial reading of 46 yields what apparent viscosity?

In a rotational viscometer set to 600 rpm, a dial reading of 46 yields what apparent viscosity?

• A. 46 cp
• B. 23 cp
• C. 15 cp
• D. 30 cp

Answer: (B)

In a rotational viscometer, the dial reading is a torque measure that must be converted to viscosity using a fixed calibration for the spindle at that speed. For 600 rpm with this setup, the dial reading is converted by multiplying by 0.5 to get the apparent viscosity in centipoise. So a reading of 46 translates to 46 × 0.5 = 23 cP. That’s why 23 cp is the correct result.

In a rotational viscometer, the dial reading is a torque measure that must be converted to viscosity using a fixed calibration for the spindle at that speed. For 600 rpm with this setup, the dial reading is converted by multiplying by 0.5 to get the apparent viscosity in centipoise. So a reading of 46 translates to 46 × 0.5 = 23 cP. That’s why 23 cp is the correct result.