Simultaneous thermal analysis, dilatometry and thermal transport answer three different questions. How to pick the two or three instruments a shared department will actually keep busy, and in what order.
A department gets one equipment grant and spends it on a single thermal analyser, usually a TGA, because that is the instrument everybody has heard of. Two years later three research groups are competing for it, one of them is using it to answer a question it cannot answer, and there is no money left. Sizing a thermal line properly means deciding at the outset how many distinct questions the department actually asks, because thermal analysis instruments are not interchangeable and a second unit of the same kind is rarely the right next purchase.
There are three families, and they answer three different questions.
A group working on refractories needs one and two. A group on thermal barrier coatings needs two and three. A group on polymers or pharmaceuticals usually only needs one. Working out which combination the department has, before the tender is written, is what stops a shared instrument being fought over.
A simultaneous thermal analyser records mass change and heat flow on the same sample in the same run. That is worth more than the two separate measurements because the two signals are on the same time and temperature axis, so a mass loss step can be tied to the endotherm that caused it without any assumption that two runs behaved identically.
The STA L81 is the general purpose instrument in the Linseis range, with interchangeable furnaces covering cryogenic through to high temperature work under vacuum or optional pressurised atmospheres. It carries the legacy designation STA PT 1600, which matters in Bangladesh because a specification copied from an older catalogue or an older tender document will still name the dead number. The STA L82, formerly the STA PT 1000, covers simultaneous TG and DSC up to 1100 degrees for routine characterisation, and the STA/TGA L86 offers two thermobalance versions and a wide furnace choice for laboratories that want one adaptable frame.
Where mass change alone is the question, a dedicated thermobalance is cheaper and easier to keep in calibration. The TGA L81 is the high temperature version with interchangeable furnaces and an optional turntable for several furnaces, and the TGA L83 is a toploading balance with an integrated thermocouple in the sample holder, which is the practical choice for decomposition, moisture, filler content and oxidation work on solids and powders.
Calorimetry splits by temperature and by sample. The DSC L63 covers melting, crystallisation, glass transition and heat capacity without a hardware change across its range. The HDSC L62 is the high temperature modular instrument for ceramics and metals, stating a temperature precision of 0.01 degrees, with an optional robot that measures up to 42 samples unattended. The Chip-DSC L66 Advanced is a compact chip sensor instrument that reaches minus 180 to 600 degrees with the matching cooling option, and the UDSC L64 is the high sensitivity unit for liquids, solids and gels, working from minus 60 to 160 degrees on 5 to 100 microlitre samples with no cleaning between runs. Reading what those traces mean, and telling a real transition from an artefact, is covered in reading a DSC trace.
Dilatometry answers the ceramics and metallurgy questions that thermogravimetry cannot: how much does this expand, at what temperature does it start to sinter, and what does it do on cooling.
| Instrument | Arrangement | Where it belongs |
|---|---|---|
| DIL L76 Horizontal | Entry level horizontal pushrod, LVDT or optical encoder, to 1600 degrees | CTE testing of ceramics, bricks, tiles, porcelain and building materials. The first dilatometer most departments should buy |
| DIL L75 Horizontal | Single, differential or double sample, LVDT or optical encoder | Expansion and sintering studies, including work under 100 per cent hydrogen |
| DIL L75 Vertical | Zero friction vertical design with a cryogenic option to minus 263 degrees | Sintering studies and expansion work over a very wide temperature range |
| DIL L75 Quattro | Four samples in one run at 0.125 nm resolution | High sample count laboratories where throughput is the constraint |
| DIL L73 Laser | Non-contact laser detection at up to 0.3 nm resolution | Expansion and shrinkage where a pushrod would load the sample |
| DIL L74 OD | Optical dilatometer, camera tracked, accuracy stated to 1 micrometre | Soft or fragile materials that a pushrod would deform |
| DIL L78 RITA | Quenching and forming dilatometer with TTT, CCT and CHT diagram software | Heat treatment development on steels, including gas quenching |
Two related instruments sit alongside these. The DIL L74 HM is a heating microscope for thermo-optical analysis, recording the sample in real time with a high resolution camera and automated focus so melting behaviour, volumetric change and contact angle can be followed, to DIN 51730 and ISO 540 among other standards. That makes it directly relevant to ash fusion and glass work. And the TMA L72 measures expansion, softening and deformation under a defined load to 1600 degrees at 0.125 nm resolution, with three point bending supported, which is the measurement to reach for when the question is dimensional stability under load rather than free expansion.
For a Bangladeshi department serving ceramics, cement, refractories and construction materials work, the DIL L76 Horizontal is usually the right first dilatometer and the DIL L78 RITA is the one to hold back for a steel or heat treatment programme that is actually funded.
The flash family covers dense, conductive samples. The LFA L51 uses a software controlled light flash with the temperature response captured at 2.5 MHz, which suits thin or highly conductive materials, with measurement stated to 1250 degrees. The LFA L52 is the high power laser version, running in inert, reducing or oxidising atmospheres or under vacuum. For thin films the TF-LFA L54 works in the range of 80 nm to 20 micrometres up to 500 degrees, with an anisotropy option giving in-plane and cross-plane values on multilayer and 2D materials, and the PLH L53 uses periodic laser heating on 10 to 500 micrometre samples across a diffusivity range of 0.01 to 2000 mm2/s.
Insulating and awkward samples need a different approach. The THB L56 is a transient hot bridge instrument giving absolute values of thermal conductivity, diffusivity and specific heat on solids, liquids, pastes and powders with a sensor simply placed against the sample, in Basic, Advanced and Ultimate levels. The HFM L57 is a heat flow meter for insulating and low conductivity materials, holding the sample between two temperature controlled plates, designed to ASTM C518, JIS A1412, ISO 8301, DIN EN 12664 and DIN 12667. For a building materials laboratory testing insulation to a published standard, the HFM is the instrument the standard names; a flash instrument is not a substitute. And for electronics and battery work, the TIM L58 measures the thermal resistance of interface materials under realistic contact pressure with evaluation to ASTM D5470.
Evolved gas analysis turns a mass loss step into a named species. The L40 EGA QMS couples a Linseis thermobalance to a Pfeiffer or MKS quadrupole mass spectrometer through a heated adapter and capillary. The L40 EGA FTIR couples an STA L81 to a Nicolet FTIR through a temperature controlled transfer line, identifying species by their infrared bands. The L40 EGA GCMS separates first and then identifies, and the L40 EGA In-Situ works optically by FTIR, Raman or ELIF down to the ppm range, which is what allows materials with high condensation temperatures such as alkali metals to be measured at all.
Gas handling belongs in the purchase. The L40 Gas Dosing series supplies and switches gases with two to four lines dosed by electromagnetic valves or mass flow controllers, in ultra high vacuum, atmospheric and high pressure versions. The L40 GASSAFETY system monitors the gases around the instrument with sensors that can be prepared for hydrogen, methane, carbon monoxide, chlorine and others, and its integrated three channel mass flow controller issues an emergency purge if a supply runs out. Where humidity or steam is part of the experiment, the L40 HUM relative humidity generator and the L40 VAPOR water vapour generator supply defined conditions to the sample atmosphere.
Software is what makes a shared instrument line workable. The Linseis L42 suite splits into three modules: Linseis L42 TA Acquisition Software runs the measurement and can drive pressure regulators, mass flow controllers and vacuum pumps; Linseis L42 TA Administration Software configures instruments, users, user groups and authorisations, material parameters and gases; and Linseis L42 TA Evaluation Software handles curve evaluation with selectable plug-ins and a Python interface for adding functions. For a facility with several groups sharing instruments, the administration module is the one that prevents a postgraduate overwriting a calibration, and it should be configured at commissioning rather than after the first incident.
One more Bangladeshi specific point. A microbalance in a room with a split air conditioner blowing across the bench shows a baseline drift nobody can explain. Site it away from the air outlet and let the room settle before the first run of the day, for the reasons set out in why your analytical balance will not settle.