Basic density testing: which of the following devices cannot be used to measure the specific gravity (relative density) of a liquid sample in a lab or field setting?

Introduction / Context:
Specific gravity (SG) is a key property in chemical, petroleum, and food industries. It can be measured by several classical devices, each suited to different sample volumes, viscosities, and accuracy requirements. Identifying which instrument is unrelated to density avoids misapplication in the lab.

Given Data / Assumptions:

• We compare common instruments used in routine SG measurements with one instrument used for something entirely different.
• Liquids are Newtonian and homogeneous.
• Room-temperature measurements are implied.

Concept / Approach:
A pycnometer (specific gravity bottle) determines density by precise mass and known volume. A hydrometer floats to an equilibrium depth tied to density via buoyancy. Digital densitometers use oscillating U-tube methods. By contrast, an anemometer measures air velocity; it is not a density meter for liquids.

Step-by-Step Solution:
Identify SG-capable tools: specific gravity bottle, pycnometer, hydrometer, digital densitometer.Recognize anemometer’s function: wind speed measurement.Therefore, select anemometer as the device that cannot measure SG.

Verification / Alternative check:
Laboratory SOPs for SG testing list hydrometers (ASTM D1298), pycnometers/specific gravity bottles (ASTM D4052 equivalents via densitometer). None mention anemometers for density.

Why Other Options Are Wrong:
Specific gravity bottle/pycnometer: Classical gravimetric density methods.Hydrometer: Float-based quick SG measurement.Digital densitometer: Modern, precise density/SG instrument.

Common Pitfalls:
Using hydrometers outside their calibrated temperature, ignoring meniscus corrections, or using pycnometers with trapped bubbles can introduce noticeable error.

Final Answer:
Anemometer