LAUDA Alpha A 24 Heating Thermostat, 25 to 100 °C, 18 to 25-litre Bath, L000621

Larger set-ups, such as several baths in series or an external circuit connected to a reactor, require more volume than a compact benchtop unit can provide. With a bath volume of 18 to 25 l, the LAUDA Alpha A 24 is the largest heating bath in the Alpha series and covers the same operating temperature range of 25 to 100 °C as the smaller models.

Large stainless steel bath vessel

The stainless steel bath vessel measures 295 x 374 x 200 millimetres internally and holds between 18 and 25 l of temperature-controlled fluid. With dimensions of 332 x 535 x 420 millimetres and a weight of around 11 kilograms, the unit requires more floor space than the smaller Alpha models, but in return offers space for larger vessels or several test specimens at the same time.

Display and control

Operation is via three buttons and a simple menu system; the single-line LED display shows the actual or setpoint value. The fully electronic, continuous controller maintains the temperature with a stability of ± 0.05 K; the operating temperature range extends from 25 to 100 °C at a permissible ambient temperature of between 5 and 40 °C.

Circulation for external circuits

The circulation pump delivers up to 15 l per minute at a maximum pressure of 0.2 bar; with a bath volume of 18 to 25 l, this is sufficient for uniform mixing and, with the optional pump connection set, also for connecting an external circuit to a double-walled vessel or reactor. The built-in safety electronics detect faults during operation with non-flammable liquids, such as an insufficient liquid level or an excessive temperature, and signal these with both an audible and a visual alarm. With a maximum heating power of 1.5 kilowatts and a current draw of 7 amperes, the large bath takes noticeably longer to heat up than the smaller Alpha models.

Typical applications

• Temperature control of larger batches and vessels with a bath volume of up to 25 l
• External circuits for double-walled reaction vessels using the optional pump connection set
• Material testing and calibration work with multiple test specimens simultaneously
• Industrial quality control with higher sample throughput
• Central temperature control bath for several connected workstations in the same room

Smaller models or active cooling

If the full capacity of 25 l is not required, the Alpha A 12 (8 to 12 l) and the Alpha A 6 (2.5 to 5.5 l) are more space-saving alternatives from the same series. If the large bath needs to be actively cooled to below ambient temperature, this is handled by the Alpha RA 24 refrigeration thermostat with compressor cooling.

Comparable values in accordance with DIN 12876

As with the smaller Alpha heating thermostats, the technical data for the Alpha A 24 has been determined in accordance with DIN 12876, the standard for circulation and bath thermostats in laboratory and industrial applications. This allows temperature stability, heating power and pump capacity to be compared with equipment from other manufacturers, which is an advantage in tendering processes or when replacing an existing large bath.

Mains connection and export variants

As standard, the Alpha A 24 operates on 220 volts at 60 hertz or 230 volts at 50 hertz; the mains plug is an angled Schuko-type plug in accordance with CEE7/7. Customers operating the unit outside Europe can order a 115-volt version with a NEMA5-15P plug using a separate order number.

Technical details

Scope of delivery

• LAUDA Alpha A 24 heating thermostat with stainless steel bath vessel, order number L000621
• Screw terminal (standard accessory)
• Flow restrictor (standard accessory)
• Mains cable with angled Schuko plug
• Operating instructions as a PDF download

Regulatory information

This device is an electrical appliance within the meaning of the German Electrical and Electronic Equipment Act (ElektroG). The WEEE registration number of the manufacturer, LAUDA DR. R. WOBSER GMBH & CO. KG, is DE 66424057. Information on the return of end-of-life equipment can be found on our Environment and Disposal page.

Warranty and procurement service

LAUDA DR. R. WOBSER GMBH & CO. KG, Lauda-Königshofen, offers end customers a 5-year ‘Best’ warranty on this device, effective from the date of delivery. This is subject to registration at lauda.de within three months of delivery and the use of genuine LAUDA temperature control fluids. The warranty covers material and manufacturing defects. Exclusions include, amongst others, wear parts such as filters and seals, damage caused during transport, damage resulting from unauthorised tampering, as well as cables, plugs, hoses and adaptors. LAUDA’s warranty terms and conditions (as at 03/2025) apply. Your statutory warranty rights remain unaffected.

Accessories available for the Alpha A 24 include a matching bath cover, a cooling coil set and a pump connection set for external circuits. LT Laborhandel will compile the appropriate accessories and spare parts for the unit on request.