Hydrometer, Twaddle

Quick Answer: The Twaddle Hydrometer reads on the Twaddle (°Tw) scale, a simplified density scale historically developed for liquids heavier than water and still used today in the textile, tanning, and dyeing industries for quick concentration checks.

Product Description

The Twaddle scale is a simplified alternative to specific gravity, designed so that whole-number readings correspond conveniently to common industrial liquid strengths — it reads zero for pure water and increases as liquid density rises above that of water. Like our other hydrometers, this instrument works by buoyancy, floating at a depth that corresponds to the density of the liquid being tested.

What Makes This Instrument Distinct

What sets this hydrometer apart from our specific-gravity and Baumé-scale instruments is its Twaddle scale, which is specifically associated with textile, tanning, and dyeing process liquids in industrial settings. Where a specific-gravity hydrometer requires a small-decimal reading, the Twaddle scale’s whole-number convention is designed to be read and communicated quickly on a factory floor.

Care & Maintenance

• Rinse thoroughly after each use, particularly after contact with dye or tanning-process liquids, to prevent residue affecting future readings.
• Handle carefully — as a glass instrument it can chip or crack from impact against hard surfaces.
• Store upright in a padded holder or case when not in use.
• Avoid sudden temperature shifts between storage and the process liquid, which can stress the glass.
• Periodically verify accuracy against a known reference standard as part of routine quality checks.

Why Choose LabEquip

LabEquip supplies hydrometers across the full range of industrial and analytical scales, including Twaddle, Baumé, and specific-gravity instruments. Browse our Measuring Instruments category, see our general-purpose Industrial Specific Gravity Hydrometer, or visit our homepage for our full catalogue.

Frequently Asked Questions

What is the Twaddle scale?
The Twaddle (°Tw) scale is a simplified density scale for liquids heavier than water, reading zero at the density of pure water and rising in convenient whole numbers as density increases.

What industries use a Twaddle hydrometer?
It is most commonly associated with the textile, tanning, and dyeing industries for quick, practical concentration checks of process liquids.

How does this hydrometer work?
Like other hydrometers, it works on the buoyancy principle — it floats at a depth that corresponds to the liquid’s density, and the Twaddle scale is read at the liquid surface.

How is the Twaddle scale different from specific gravity?
Twaddle is a simplified, whole-number scale specifically calibrated for liquids denser than water, designed for faster factory-floor reading than the small-decimal specific-gravity convention.

Can this hydrometer be used for liquids lighter than water?
No — the Twaddle scale is specifically designed for liquids heavier than water. For general-purpose measurement, our specific-gravity hydrometer may be more suitable.

How should I maintain this hydrometer?
Rinse it after each use, particularly after contact with dye or tanning liquids, handle it carefully, and store it upright in a padded holder.

Last Updated: September 2026