Gooch Crucible, Low form, With Sintered Disc

Quick Answer: A low form Gooch crucible with sintered disc is a short, wide filter crucible whose base is a porous fused disc, used to collect, dry and weigh precipitates in gravimetric analysis. It sits in a filter tube on a suction flask, so the precipitate is filtered, washed, dried and weighed in the same vessel.

Filter, Dry and Weigh in One Vessel

The original design, devised by the American chemist Frank Austin Gooch in the 1870s, was a porcelain crucible with a perforated base covered by a mat of asbestos fibres. Sintered disc crucibles replaced the mat with a permanent porous plate fused into the base, which is quicker to prepare and avoids handling fibres. The crucible is weighed empty, the precipitate is filtered onto the disc under suction, and after washing and drying the crucible is weighed again; the difference is the mass of the precipitate.

Low form means the crucible is shorter and wider than the standard pattern. A wider disc spreads the precipitate thinly, which speeds filtration and drying, and the lower profile stands steadily in a desiccator and on the balance pan. The title does not name the crucible material or porosity grade; crucibles listed this way are usually glass with a fused frit, but confirm both, along with capacity, when ordering.

The crucible is held on the filtering flask in a filter tube for Gooch crucibles with a rubber collar that seals around its wall. Between weighings it cools in a borosilicate glass desiccator.

Specifications

Applications

• Determining nickel as the bright red nickel dimethylglyoximate precipitate, dried in an oven before weighing
• Gravimetric determination of chloride as silver chloride, kept out of strong light
• Finding the insoluble matter in reagents, fertilisers or building materials by filtering and weighing the residue
• Undergraduate analytical practicals on precipitation, washing and drying technique

Care & Handling

• Bring the empty crucible to constant mass under the same drying conditions that will be used for the precipitate.
• After weighing, dissolve the precipitate out with a suitable reagent, such as dilute ammonia for silver chloride, then rinse with water.
• Heat and cool gradually in an oven, and do not place a glass crucible directly in a flame.
• Handle the dried crucible with tongs or lint-free tissue, because fingerprints add measurable mass.

Why Choose LabEquip

Analytical chemistry courses and quality control laboratories that still rely on gravimetric methods need crucibles that can be tared, filtered into and weighed repeatedly. LabEquip lists the low form crucible in its chemistry lab equipment; specify porosity and capacity through the contact page.

Frequently Asked Questions

How does a sintered disc crucible differ from the original design?

The original used a perforated porcelain base covered with a prepared fibre mat. A sintered disc crucible has a permanent porous plate fused into the base, so no mat has to be made, and it can be cleaned and reused.

Why choose the low form?

The shorter, wider shape spreads the precipitate over a larger area, so it filters, washes and dries faster. It also stands more steadily in a desiccator and on a balance pan.

How is the crucible fitted to the suction flask?

It rests in a filter tube or holder, sealed by a rubber collar around the crucible wall, and the tube’s stem goes through a bored stopper in the neck of the flask. Suction then draws liquid only through the disc.

What is meant by drying to constant mass?

The crucible and precipitate are dried, cooled in a desiccator and weighed, and the cycle is repeated until two successive weighings agree within the limit set by the method. Only then is the mass taken as final.

How do I clean the disc after an analysis?

Dissolve the precipitate with a suitable reagent drawn through under suction, for example dilute ammonia for silver chloride or dilute hydrochloric acid for many metal hydroxides, then flush with plenty of water and dry slowly.

Can the crucible be heated in a muffle furnace?

Glass frit crucibles tolerate oven drying and moderate heating when warmed and cooled slowly, but high-temperature ignition calls for porcelain or platinum. Check the maximum temperature for the crucible you receive before heating it strongly.

Last Updated: September 2026