Three numbers
from one sample.
Moisture, volatile matter and loss on ignition are three separate tests, each with its own standard and, normally, its own sample and weighing. The VLOI-FA takes a single sample from room temperature up through all three holds and reports the lot.
Each hold answers a different question.
Water leaves first, then the volatiles, then what remains burns at ignition temperature. Holding the sample at each step in turn separates the three, so one weighing gives three figures that used to need three tests.
Moisture
Free water in the sand. It drives compactability and the way the mould behaves at the machine, and it changes hour by hour.
Volatile matter
What comes off before ignition: sea coal and carbon carriers in green sand, lighter binder fractions in bonded sand. A lever behind gas defects and finish.
Loss on ignition
What burns at ignition temperature. In green sand it tracks the residue building up in the system; on a coated grain it indicates the binder present.
It climbs, waits, and moves on by itself.
The unit starts at room temperature and walks up through the three holds. At each one it watches how fast the weight is still falling, and steps up once that rate has settled and stayed settled.
Weigh, once
The sample is weighed on the balance built into the unit. The same sample carries through the whole run.
Hold for moisture
The furnace settles at the moisture temperature and stays there until the weight stops falling.
Hold for volatiles
It steps up to 482 °C, the volatiles temperature, and again waits for the weight to settle.
Hold for ignition
A final step to 982 °C burns off what remains. When the weight settles, the run ends on its own.
A timer suits one sand. The weight suits them all
Fixed step times are set for a particular mix, so a wetter sand can move on before it is dry and a heavier binder can be cut short. Ending each hold on the weight keeps one sand comparable with the next, and it also means the run takes as long as the sample needs rather than a fixed block of time.
The temperature setpoints are yours to set. AFS values are loaded by default, and they can be changed to match BIS, EN or a house method without altering how the run decides to move on.
The value of the figures is in the trend.
A single set of readings says what one sample held. Plotted batch by batch against limits set from the process, they show whether the sand system is holding station or drifting, and they do so before the castings report the problem.
Readings sync through V-Sync, so the batch history builds on its own and a supervisor can look at the trend from a browser. See how V-Sync works →
Every reading carries its own paperwork.
A figure on its own is hard to defend six months later. Each run is stored complete: what was tested, who tested it, when, and the settings that produced the number.
Named before it starts
A run will not begin without a sample number. Batch, material, line and operator are captured alongside it, so a reading can always be traced back to the sand it came from.
Settings stored with the result
The temperatures, the settling rule and the hold limits in force during that run are saved with it. A figure measured under different settings is a different measurement, and the record says which was used.
A record you can hand over
Every test produces a printable record: the three readings, the curve, the sample details and how each hold ended. It prints on one page for a file or a customer.
Nothing quietly dropped
Practice runs are marked as practice. A run that was stopped early is kept and labelled, because an operator often stops a test for a reason worth keeping.
An audit asks how, not just what
Recording the reading is the easy part. What is usually missing is the method that produced it, and that is the part an assessor asks about. Holding both together lets a figure be reproduced later, or defended, without anyone relying on memory.
The furnace reports its own condition.
Every test drives the furnace hard, which makes each run a free measurement of the equipment. Four things are tracked from run to run and compared against how the machine behaved when it was new.
A trend is called by comparing the earliest runs against the most recent ones, and small movements are reported as steady rather than raised as findings. The intention is a service visit that is planned, not one that follows a failure.
The rate of loss, read against temperature.
Alongside the three holds, the unit can run a slow controlled climb and record how fast weight is leaving at every temperature on the way up. The three holds tell you how much was lost. This tells you where it went.
Each rise in the curve is something leaving the sample at its own temperature. The technique is established: published work on foundry green sand reports that a single controlled heating run can be used to work out the moisture, and the amounts of seacoal, bentonite and quartz, from the one sample.
| Around | What is leaving | What it can tell you |
|---|---|---|
| 100 °C | Free and interlayer water | Moisture, separated from anything that burns later |
| 300 to 500 °C | Seacoal and other carbon carriers, resin | How much carbonaceous additive is still active in the system |
| 500 to 750 °C | Clay, losing its structural water | Indication of how much bentonite is still live rather than burnt out |
| 600 to 850 °C | Carbonates | Carbonate pick-up, where it is present |
| 800 to 950 °C | Remaining carbon | What is left to burn at the ignition hold |
Two honest limits. The clay and carbonate ranges overlap between roughly 600 and 750 °C, so a rise there can be either and is not on its own proof of one. And peak positions shift with how fast the sample is heated, so runs are only comparable with each other when the same heating rate was used. The rate is stored with every run for that reason.
Live clay is the number the mix is actually run on
Active clay is normally established by a separate methylene blue titration, on a separate sample, at a separate bench. A heating curve approaches the same question from the other direction and on the sample already in the machine. It is offered as an indication to be read alongside the titration, not as a replacement for it.
The numbers a lab plans around.
Supplied with the main unit, three refractory crucibles and tongs. A Class F1 or E2 weight set and a temperature verification kit are recommended alongside, and the installation needs ventilation with an exhaust.
| Test | Combined moisture, volatile matter and loss on ignition, in one run |
|---|---|
| Method | AFS 5305-18-S, quick moisture, volatile materials and loss on ignition (loss on ignition alone, AFS 5100-12-S) |
| Stages | Moisture hold, volatiles hold, ignition hold, run in sequence on one sample |
| Temperatures | Setpoints are adjustable to suit the standard in use. AFS values: volatiles 482 °C (900 °F), ignition 982 °C (1800 °F) |
| Step ending | Each hold ends when the rate of weight change settles, rather than on a fixed timer |
| Results | Three readings and the weight loss curve from a single sample |
| Range | Weight loss 0 to 100 per cent |
| Balance | Integrated, ±0.05 g |
| Sample mass | 30 g green sand, for a steadier reading and less sampling error; 8 ±3 g bentonite or pre-blends |
| Data | Wired network connection, optional Wi-Fi, V-Sync cloud sync |
| Size · weight | 780 × 760 × 410 mm · about 26 kg |
| Traceability | Traceable to national standards, NABL-traceable calibration at least once a year |
| Power | 230 V AC, 50 Hz standard; other supplies such as 110 V, 60 Hz on request |
The furnace runs hot. Let it cool before handling crucibles and use the tongs supplied.
Run it on your own sand.
Send a sample or book a demonstration, and we will show the three readings and the curve the mix actually gives, with the record it leaves behind.