Many laboratory tasks need two things at once: controlled heat and uniform mixing. A hotplate magnetic stirrer delivers both through a single tabletop unit — cutting bench time, simplifying setups, and removing the need for separate heating and agitation equipment. This guide explains the working principle, step-by-step usage, practical applications, and the mistakes that slow labs down.
Two fully independent mechanisms run at the same time. The heating system warms the plate surface through a resistive element managed by a PID controller. The magnetic system spins a drive magnet beneath the plate, which couples with a PTFE-coated stir bar placed inside the vessel — rotating it without any moving parts above the surface.
An electric motor below the plate spins a drive magnet. Its rotating magnetic field passes through the plate surface and locks onto the PTFE stir bar placed inside the vessel. The bar rotates in perfect sync — no moving parts contact the liquid, so cross-contamination risk is minimal.
An embedded heating element raises the ceramic plate temperature. A PID (proportional-integral-derivative) controller continuously compares the measured temperature against your set point and adjusts power output to hold ± 1 °C stability — even as external conditions change.
The sequence below applies to most buffer and reagent preparation tasks. Following this order avoids the most common errors — particularly stir bar decoupling and thermal overshoot.
The hot plate and stirrer combination fits across a wide range of laboratory environments. Each application below uses both heating and agitation — the defining capability of this instrument class.
Dissolving buffer salts requires both heat to speed kinetics and stirring to prevent localised concentration gradients. The lab hot plate with magnetic stirrer handles both simultaneously, cutting preparation time significantly.
Staining reagents, specimen preparation, and diagnostic kit reconstitution all require consistent temperature and agitation. Controlled mixing avoids stratification in long-run assay workflows.
API dissolution studies, USP dissolution testing, and stability trials all depend on the heated magnetic stirrer maintaining both a precise temperature and a defined stir rate across the full test window.
Agar dissolution, broth preparation, and selective media formulation all need heat to dissolve powders and stirring to prevent local scorching — a common cause of growth inhibition in prepared media.
BOD sample preparation, heavy metal digestion, and titration reactions use the hot plate magnetic stirrer to maintain consistent agitation at exact temperatures, improving batch-to-batch repeatability.
A single unit with LCD feedback replaces two separate instruments for student setups. The visual display helps trainees directly observe the relationship between heating input and solution temperature.
| Parameter | Value / Range | Standard / Compliance |
|---|---|---|
| Temperature Range | RT to 380 °C | ISO 3696 |
| Temperature Stability | ± 1 °C | IEC 61010-1 |
| Speed Range | 100 – 2000 rpm | ISO 9001 |
| Max. Stirring Capacity | 10 L (H₂O) | ASTM E1273 |
| Plate Material | Ceramic-coated / Stainless Steel | EN 61010 |
| Display | LCD (simultaneous temp + speed) | — |
| Motor Type | DC Brushless | IEC 60034 |
| Over-Temperature Protection | Adjustable safety cutoff | CE Marked |
| Power Supply | 220–240 V, 50/60 Hz | ISO/IEC 17025 |
| Certifications | CE, ISO 9001:2015, GMP | GMP |
Verify current certification status with Fison prior to procurement.
A multi position hot plate stirrer extends the platform to carry multiple vessels simultaneously — each with its own PTFE stir bar — sharing one heating element and one or more speed controls. This is the difference between running one experiment and running six at the same time.
These are the errors that appear repeatedly in teaching labs and quality-control environments. Most are simple to prevent once you know the cause.
Jumping straight to high rpm causes the stir bar to lose magnetic coupling — it starts spinning off-centre or stops entirely. Always start below 200 rpm and ramp upward gradually until stable rotation is confirmed.
The plate surface temperature is not the same as the liquid temperature inside your vessel. A 20–40 °C gap is common at higher set points. Always verify liquid temperature with an external calibrated probe — never assume the display reading reflects what is inside the flask.
A bar too short for a large vessel creates dead zones at the edges. A bar too large for a small flask causes splashing and instability. The stir bar length should be roughly one-third of the vessel's internal diameter.
Turn off heating first, then wait for the hot-surface indicator to clear before moving the vessel. Most thermal burns happen when technicians handle vessels that feel cooler than the plate actually is.
For any low-boiling solvent, use a watchglass or condenser. Evaporation changes concentration, alters your reaction stoichiometry, and creates vapour accumulation in enclosed spaces.
Stir bars lose magnetic coupling strength over time, especially in high-frequency use labs. Bars used daily in aggressive solvents should be replaced or demagnetised every few months to maintain consistent performance.
Each function below operates as part of a coordinated system. Understanding what each component does helps you configure the instrument correctly and interpret its readings accurately.
The FM-HMS-A105 is one model within a broader family of magnetic stirring instruments. Depending on your application — flask size, sample viscosity, number of simultaneous runs, or heating requirements — a different format may be the better fit. All models sit under the Fison Magnetic Stirrer category.
View full specifications, request a quote, or speak to a Fison product specialist.