Laboratory & Muffle Furnaces
A laboratory furnace, often called a muffle furnace, is a fully enclosed, electrically heated chamber used to expose a small material sample to a precisely controlled high temperature — isolated from the flame or combustion products of the heating elements themselves. Ecotao's range covers chamber sizes from 5 litres to 30 litres and operating temperatures from 1000°C up to 1500°C, built for general laboratory ashing and heat treatment, coal volatile-matter and ash testing, and high-temperature XRF bead preparation.
We offer a range of general-purpose laboratory furnaces below, and on request can also source specialised furnaces — see specialist and industrial furnace ranges further down this page.
Full technical detail for the general-purpose range is available in our furnace specification sheet (PDF).
How to choose the right furnace
The right furnace for your lab comes down to matching four things to your method or application: temperature range, chamber volume, thermocouple/control type, and the power supply available at the installation point.
Temperature range
General ashing and heat treatment tops out at 1200°C (9L/30L muffle range). Coal volatile-matter and ash testing runs to 1000°C. XRF bead preparation with aggressive fluxes needs 1400–1500°C.
Chamber volume
Match chamber size to typical batch size and load frequency — from the compact 5L volatile furnace to the 30L muffle furnace for higher-throughput ashing and heat treatment.
Thermocouple & control
Type K suits the 1000°C economy/volatile/ashing range. Type N duplex sensors give independent control and safety readings on the 1200°C muffle range. Type R duplex sensors hold accuracy above 1200°C on the high-temperature range.
Element access
Side-wall slab elements on the muffle and economy ranges are user-replaceable. Top-mounted silicon carbide elements on the 15L high-temperature range are packed separately and need on-site installation.
Power supply
The 16L, 5L and 7.6L range runs on standard 230V/50Hz single-phase supply. The 15L high-temperature furnaces draw 5500–6500W — confirm circuit rating before ordering.
Lead time
All furnaces below are assembled to order, typically 2–4 weeks. Tell our sales team your intended application before ordering — options like the ashing accessory are configured at assembly.
Our laboratory furnace range
Every model below links through to its own product page on the Ecotao Store for current stock status. Prices are excluded from this page by design — check the store listing or contact our sales team for a current quotation.
30L Muffle Furnace – Slab Element (930)
A high-throughput, general-purpose muffle furnace for laboratories running larger sample batches. Side-wall slab elements and a type N duplex thermocouple give independent control and safety sensing, with a door-mounted sampling port so you can check progress without opening the chamber and losing heat.
- Chamber: 30 L
- Max. temperature: 1200°C (1150°C continuous)
- Thermocouple: Type N duplex
- Lead time: Assembled to order, 2–4 weeks
9L Muffle Furnace – Slab Element (909)
The compact counterpart to the 30L unit, sharing the same slab-element construction, type N duplex thermocouple and door-mounted sampling port — sized for benches running smaller or lower-frequency sample batches without giving up control precision.
- Chamber: 9 L
- Max. temperature: 1200°C (1150°C continuous)
- Thermocouple: Type N duplex
- Lead time: Assembled to order, 2–4 weeks
16L Economy Furnace
A versatile everyday furnace for general lab heat-treatment work spanning annealing, ashing, calcination, curing, drying, loss-on-ignition, sintering and fusion — a good default choice when a lab needs one furnace covering several routine processes rather than a test-specific unit.
- Chamber: 16 L
- Max. temperature: 1000°C continuous
- Power: 3300W, 230V/50Hz
- Thermocouple: Type K
5L Volatile Furnace
Purpose-built for coal volatile-matter determination, where the test method depends on the sample reaching a set temperature within a fast, specific heating window before oxidation begins. The digital setpoint control and solid-state switching are tuned for that rapid, repeatable ramp rather than general-purpose heat treatment.
- Chamber: 5 L
- Max. temperature: 1000°C continuous
- Power: 3500W, 230V/50Hz
- Thermocouple: Type K
7.6L Ashing Furnace
Designed for coal ash determination, where the test method requires the sample to be ashed in a preheated airflow for uniform results. The chamber and control system are matched to that specific airflow-ashing procedure rather than sealed static-chamber heat treatment.
- Chamber: 7.6 L
- Max. temperature: 1000°C continuous
- Power: 3500W, 230V/50Hz
- Thermocouple: Type K
15L High Temperature Furnace (931)
Built for bead preparation with aggressive fluxes ahead of XRF analysis, where 1000°C-class furnaces can't fully fuse the sample. Top-mounted silicon carbide elements and a type R duplex thermocouple hold accuracy at higher temperatures than the type K/N sensors used lower down the range.
- Chamber: 15 L
- Max. temperature: 1400°C
- Power: 5500W
- Thermocouple: Type R duplex
15L High Temperature Furnace (932)
The higher-power sibling of the 931, for fluxes or samples that need the extra 100°C of headroom to fully fuse. Same 15L chamber, top-mounted silicon carbide elements and type R duplex thermocouple, stepped up to a 6500W element set for the higher ceiling.
- Chamber: 15 L
- Max. temperature: 1500°C
- Power: 6500W
- Thermocouple: Type R duplex
Compare the full range
← Scroll to see full table →
| Model | Chamber | Max. temperature | Power / supply | Thermocouple | Primary application |
|---|---|---|---|---|---|
| 9L Muffle Furnace (909) | 9 L | 1200°C (1150°C cont.) | — | Type N duplex | General-purpose ashing & heat treatment, smaller batches |
| 30L Muffle Furnace (930) | 30 L | 1200°C (1150°C cont.) | — | Type N duplex | General-purpose ashing & heat treatment, higher throughput |
| 16L Economy Furnace | 16 L | 1000°C | 3300W, 230V/50Hz | Type K | Annealing, ashing, calcination, curing, drying, LOI, sintering, fusion |
| 5L Volatile Furnace | 5 L | 1000°C | 3500W, 230V/50Hz | Type K | Coal volatile-matter testing (fast heating profile) |
| 7.6L Ashing Furnace | 7.6 L | 1000°C | 3500W, 230V/50Hz | Type K | Coal ash determination, preheated airflow |
| 15L High Temp. Furnace (931) | 15 L | 1400°C | 5500W | Type R duplex | XRF bead preparation with aggressive fluxes |
| 15L High Temp. Furnace (932) | 15 L | 1500°C | 6500W | Type R duplex | XRF bead preparation, highest-temperature fusion work |
What these furnaces are used for
Ashing & loss-on-ignition
Ashing burns off the organic fraction of a sample at a controlled temperature so the remaining mineral or ash content can be weighed and calculated as a percentage of the original mass — the basis of loss-on-ignition (LOI) testing across soils, feeds, foods and minerals. Ecotao's muffle and economy furnace ranges hold a stable chamber temperature through the full burn cycle, and the door-mounted sampling port on the 9L/30L range lets you check progress without opening the chamber and losing accumulated heat, which would otherwise distort the result.
Coal & solid-fuel testing
Standard coal test methods for volatile matter and ash content specify not just a target temperature but the rate at which the sample must reach it. The 5L Volatile Furnace and 7.6L Ashing Furnace are built around that constraint specifically — solid-state switching and digital setpoint control give the fast, repeatable heating ramp the methods call for, rather than the slower general-purpose ramp of a standard muffle furnace.
XRF bead preparation & high-temperature fusion
Preparing a fused bead for X-ray fluorescence analysis means dissolving a solid sample into a borate flux at a high enough temperature to fully melt and homogenise it — typically well above what a 1000–1200°C furnace can sustain. The 15L High Temperature Furnace range uses top-mounted silicon carbide elements, rather than side-wall slab elements, to reach 1400°C (model 931) or 1500°C (model 932), with type R duplex thermocouples holding measurement accuracy at those temperatures where type K and type N sensors lose precision.
Annealing, calcination, sintering, curing & drying
These are the routine, everyday processes most labs run through a single general-purpose furnace rather than a test-specific unit — relieving internal stress in metals or ceramics (annealing), decomposing a compound thermally (calcination), fusing particles below melting point (sintering), or driving off moisture or curing a coating (drying/curing). The 16L Economy Furnace is sized and priced for exactly this everyday role.
Specialist & industrial furnace ranges
Beyond the general-purpose range above, we can source furnaces for specialist applications on request — including the Nabertherm range for industry, art and crafts, laboratory, dental and process-control use. Other fields of application include fibre optics (glass), thermal process technology for air, gases and vacuums, advanced materials and additive manufacture, and foundry work.
The right furnace type for a specialist application depends on several factors we'll work through with you before quoting:
- Required temperature range
- Charge dimensions
- Type of protective or reaction gas
- Required leak rate of the work space / required surface quality of the charge
- Safety requirements — for example, when working under flammable gases
- Required heating and cooling times
Depending on your process requirements, we can offer adapted solutions for heat treatment, including quenching. Contact our sales team with your application details to get a specification match.
Furnaces & South African lab conditions. The 16L Economy, 5L Volatile and 7.6L Ashing furnaces are specified at 230V/50Hz, matching standard South African single-phase laboratory supply directly — no step-up or conversion needed. The 15L High Temperature range draws more current at 5500–6500W, so it's worth confirming your installation point's circuit rating before ordering.
All furnaces on this page are assembled to order rather than held as finished stock, with a typical 2–4 week lead time. Our sales team will ask about your intended application before confirming an order, since options like the ashing accessory and programmable controllers are configured at the assembly stage — get in touch early in your procurement process to keep that lead time on track.
Frequently asked questions
What is a muffle furnace used for?
A muffle furnace is an electrically heated, fully enclosed chamber used to expose a sample to a controlled high temperature while isolating it from the heating elements' own combustion products. In a lab, that's used for ashing, loss-on-ignition testing, annealing, calcination, sintering and general heat treatment of small material samples, where a stable, repeatable chamber temperature matters more than throughput.
What is the difference between a muffle furnace and a volatile or ashing furnace?
A general-purpose muffle furnace, like the 9L and 30L slab-element units, is built for a broad range of heat-treatment work up to 1200°C. Volatile and ashing furnaces, like the 5L Volatile Furnace and 7.6L Ashing Furnace, are purpose-built for specific coal-testing methods: the volatile furnace targets the fast heating rate needed to measure volatile matter released before oxidation, while the ashing furnace targets ash determination in a preheated airflow. Both max out at 1000°C continuous with type K thermocouples, matching what those test methods require.
What temperature does a furnace need to reach for XRF bead preparation?
XRF bead preparation uses aggressive borate fluxes that need sustained high heat to fully fuse a sample. Our 15L High Temperature Furnace comes in two power ratings for this: model 931 reaches 1400°C on a 5500W element set, and model 932 reaches 1500°C on a 6500W element set. Both use type R duplex thermocouples, which hold accuracy at these temperatures better than the type K or N sensors on lower-temperature furnaces.
How do I choose the right furnace size and thermocouple type for my application?
Start with the temperature your method or standard specifies, then match chamber volume to your typical batch size and load frequency. General ashing and heat treatment to 1200°C suits the 9L or 30L muffle range. Coal volatile-matter or ash testing to 1000°C needs the 5L or 7.6L purpose-built test furnaces. Fusion work above 1200°C, like XRF bead preparation, needs the 15L high-temperature range with type R thermocouples. Also check the power supply at your installation point — the 15L range draws more current than the 230V single-phase economy range.
What is the difference between the 15L High Temperature Furnace models 931 and 932?
Both are 15-litre chamber furnaces with type R duplex thermocouples and top-mounted silicon carbide elements, built for the same XRF bead-preparation and high-temperature fusion work. The difference is heating capacity and top temperature: model 931 runs 5500W to a maximum of 1400°C, while model 932 runs 6500W to a maximum of 1500°C. Choose the 932 if your flux or sample needs the extra 100°C of headroom.
Do these furnaces run on standard South African power supply?
The 16L Economy Furnace, 5L Volatile Furnace and 7.6L Ashing Furnace are all specified at 230V/50Hz, matching standard South African single-phase lab supply directly. The higher-wattage 15L High Temperature models draw more current at 5500W and 6500W, so it's worth confirming the circuit rating at your installation point before ordering — our sales team can advise as part of the pre-order application review.
How long does it take to receive a furnace after ordering?
Our laboratory furnaces are assembled to order rather than held as finished stock, with a typical lead time of two to four weeks. Our sales team will ask about your intended application before confirming an order, since options such as the ashing accessory and programmable controllers are configured at the assembly stage.
Need help choosing the right furnace?
Tell us your application, sample type and target temperature, and our sales team will match you to the right model and configuration before you order.