LAC PP20/45 Air-Circulating Box-Type Tempering Furnace (Max 450 °C)

Overview

The LAC PP20/45 is a precision-engineered, air-circulating box-type tempering furnace designed for controlled heat treatment processes in laboratory and light industrial environments. Operating on the principle of forced convection via an integrated axial circulation fan, it ensures uniform thermal distribution across the entire working chamber—critical for repeatable tempering, stress-relieving, aging, and low-temperature annealing applications. Unlike static muffle furnaces, the PP20/45 maintains temperature stability within ±1 °C across its 300 × 200 × 350 mm (W × H × D) stainless steel chamber, meeting the spatial uniformity requirement of DIN 17052-1 (ΔT ≤ 10 °C). Its maximum operating temperature of 450 °C is optimized for post-machining tempering of tool steels, aluminum alloys, and polymer composites—processes where over-tempering must be rigorously avoided. The furnace employs high-resistivity stainless steel heating elements and non-contact solid-state relays to eliminate mechanical switching noise and enhance long-term reliability under cyclic thermal loads.

Key Features

• Forced-air convection system with adjustable axial fan for consistent thermal homogeneity and minimized vertical/horizontal gradients
• Robust 304 stainless steel chamber and high-temperature insulation architecture engineered for >10,000 operational hours at 450 °C
• HT40AL digital controller preconfigured for 450 °C operation: supports two independent ramp-and-soak profiles with real-time setpoint tracking and auto-tuning PID algorithm
• Benchtop form factor (PP20 variant) with manually operated side-hinged door; optional hydraulic or pneumatic lift mechanisms available for ergonomic access
• Integrated safety interlock system: door-open cutoff, overtemperature cutout (independent from main controller), and thermal fuse redundancy
• Standard K- or N-type thermocouple input with cold-junction compensation and optional traceable calibration certificate (NIST-traceable)
• Low-noise operation enabled by solid-state relay switching and vibration-damped fan mounting

Sample Compatibility & Compliance

The PP20/45 accommodates standard crucibles, ceramic boats, and metal trays up to 200 mm in height. Its compact internal volume and precise airflow design make it suitable for small-batch metallurgical samples, calibration standards, and QC specimens requiring reproducible thermal history. The furnace conforms to DIN 17052-1 for temperature uniformity verification and supports GLP-compliant workflows when paired with optional HTMonit software and RS232/EIA-485 interfaces. While not intrinsically rated for hazardous atmospheres, the semi-hermetic configuration (optional) enables manual or automated inert gas purging (N₂, Ar) for oxidation-sensitive treatments—subject to user-provided gas supply and flow control hardware. All electrical components comply with CE marking requirements per EN 61000-6-3 (EMC) and EN 61000-6-4 (immunity).

Software & Data Management

The HT40AL controller provides local parameter setting and real-time display but does not include data logging. For audit-ready documentation, the optional HT205 controller (upgradable) delivers 30 programmable recipes (15 steps each), LAN connectivity, and full compliance with FDA 21 CFR Part 11 when used with HTMonit v3.x—offering electronic signatures, user role management, and immutable audit trails. Raw thermocouple output can be logged externally via RS232 or EIA-485 using third-party SCADA systems. Optional graphical temperature recorder integrates directly into the front panel, delivering time-stamped analog/digital hybrid charts compliant with ISO/IEC 17025 record retention guidelines.

Applications

• Tempering of hardened carbon and alloy steels (e.g., AISI 1045, 4140, H13) following quenching
• Stress relief of welded assemblies and machined castings prior to dimensional inspection
• Aging treatments for precipitation-hardened aluminum alloys (e.g., 2024-T3, 7075-T6)
• Pre-bake conditioning of ceramic substrates and sensor housings
• Low-temperature polymer crosslinking and outgassing protocols (e.g., epoxy encapsulants, silicone gels)
• Calibration reference oven for secondary temperature sensor validation (traceable to ITS-90)

FAQ

Does the PP20/45 support programmable multi-step thermal cycles?
The standard HT40AL controller supports two ramps and two soaks. For full multi-step programming (30 recipes × 15 steps), the HT205 controller must be specified as an option.
Can the furnace operate under inert gas atmosphere?
Yes—only when equipped with the optional semi-hermetic housing and manual/automated gas inlet kit. Standard configuration is ambient-air only.
Is cooling rate controllable?
Unassisted cooling follows natural convection decay. Controlled forced cooling is available as an accessory—but incompatible with semi-hermetic models due to pressure integrity constraints.
What maintenance intervals are recommended for long-term accuracy?
Annual verification of thermocouple calibration and fan performance is advised. Chamber insulation integrity should be assessed every 2,000 operating hours or after any thermal shock event.
Is the furnace compatible with laboratory LIMS or MES integration?
Via optional HT205 + HTMonit + EIA-485, yes—supporting Modbus RTU protocol for bidirectional communication with enterprise systems.