Nabertherm LE 1/11 Compact Muffle Furnace, R7 Controller, 1100 °C, LE013K17N1

Thermodynamic infrared transmission and quartz glass encapsulation

In analytical gravimetry and preparative ashing, the thermal decomposition of organic and inorganic matrices requires extremely steep heating rates and complete temperature homogeneity. The Nabertherm LE 1/11 operates as a thermodynamic high-temperature furnace with a maximum operating temperature of 1100 °C on a 1-litre scale. Thermal energy is supplied via heating elements arranged on both sides. These are hermetically sealed within high-purity quartz glass tubes. This specific materials-science architecture generates an excellent infrared transmittance for heat radiation. At the same time, the silicate glass physically protects the metallic heating elements from corrosive exhaust gases, halogens or acid vapours produced during the pyrolysis of the samples. This prevents the oxidative degradation of the heating elements and guarantees constant isochoric heat transfer.

Metrological cybernetics and PID control (Controller R7)

The R7 cybernetic module controls the thermal vectors. This digital PID temperature controller is metrologically designed for continuous isothermal operation at a defined target value (single setpoint). The control loop measures the actual thermodynamic value at the centre of the furnace via an integrated thermocouple and modulates the 1.5 kW electrical heating power in an anticipatory manner. This algorithm physically eliminates thermal overshoot. Power control is achieved via wear-free, pulse-switching solid-state relays. This guarantees absolutely silent operation without mechanical contact wear and enables extremely high-frequency switching cycles to maintain precise temperature stability.

Double-walled system structure and thermal containment

The continuous application of 1100 °C requires substantial thermodynamic insulation. The housing of the LE 1/11 is constructed using a structural double-walled architecture made of textured stainless steel sheet. A forced convective cooling air flow circulates between the red-hot combustion chamber and the outer skin. This keeps the external surface temperatures at a level that is safe from an occupational health perspective and protects the sensitive control electronics from thermal degradation. The interior is lined with a non-classified high-temperature fibre insulation, which drastically minimises conductive heat loss. When open, the front mechanical hinged door acts as a highly resistant ceramic work surface. This allows the user to place red-hot crucibles on it in a thermodynamically safe manner before transferring them to the desiccator using tongs.

Technical details

Thermodynamics & Heating Technology

• Maximum operating temperature (Tmax): 1100 °C
• Recommended continuous operating temperature: approx. 1050 °C
• Heating elements: On both sides (left/right), encapsulated in quartz glass tubes
• Insulation material: Fibre insulation (not classified as carcinogenic according to TRGS 905 / Class 1/2)
• Heating time (to Tmax): approx. 25 to 35 minutes (unloaded, voltage-dependent)

Metrology & Control Technology

• Controller architecture: R7 (digital PID control)
• Adjustable parameters: 1 target temperature (single setpoint)
• Power circuit: Silent solid-state relays (semiconductor contactors)
• Temperature measurement: Integrated high-temperature thermocouple (type N or S)

Chamber Infrastructure & Dimensions

• Total internal chamber volume: 1 litre
• Internal system dimensions (W x D x H): 90 x 115 x 110 mm
• External system dimensions (W x D x H): 290 x 280 x 410 mm
• Door design: Mechanical hinged door (can be used as a ceramic shelf)
• Machine weight: approx. 10 kg
• Housing material: Double-walled textured stainless steel sheet
• Exhaust system: Integrated exhaust vent in the rear wall of the oven

Safety & Electrical

• Voltage / Phase configuration: 230 V / single-phase (L/N/PE)
• Mains frequency: 50/60 Hz
• Rated electrical power: 1.5 kW
• Protection class (to DIN EN 60529): IP 20

Scope of delivery

• 1 x Nabertherm LE 1/11 compact muffle furnace
• 1 x R7 controller (permanently integrated)
• 1 x IEC power cable (Schuko)

(Important note: Heat-resistant crucibles, crucible tongs, personal protective equipment or flues for exhaust gas extraction are not included in the scope of delivery!)

Individual requirements & accessories

The Nabertherm LE 1/11 generates extreme thermal energy in a minimal amount of space. The incineration of organic matrices (e.g. plastics, agricultural products or soils) produces massive quantities of reactive pyrolysis gases. To prevent contamination of the laboratory atmosphere, it is essential to install a suitable Nabertherm exhaust flue (with or without an integrated fan) at the rear exhaust vent and connect it to the laboratory exhaust system. For the safe handling of red-hot porcelain or platinum crucibles, you must use heat-resistant crucible tongs and Kevlar protective gloves approved by occupational health authorities. Please contact our procurement service at any time to discuss the configuration of your high-temperature infrastructure.