Spiking Operations on the CAL3K Calorimeters

The following information applies to the : CAL3K-AP , CAL3K-A , CAL3K-F.

The spiking method is called for when a sample has a very low CV or burns reluctantly. Then a better burning material is added to the sample to help the process. The better burning sample is the spike.

The ‘Spike’ must be of a known calorific value, usually benzoic acid of approx. 26.454MJ/Kg. On some occasions a Gelatine Capsule (CAL2K-4-GC) or Crucible Cover Disc (CAL2K-FLDS) needs to be as a Spike.

A Gelatine Capsule is used when burning:

Fine powdery substances, which ‘scatter’ easily
Benzoic acid powder

A crucible cover disk is used when burning:

Volatile samples

STEP BY STEP ENTERING THE SPIKE MASS

Place the crucible on the Balance.
Press “Tare” to clear the weight of the crucible and get to 0.0000g
Place one Benzoic Acid tablet (as a spike) and note the Mass = Spike Mass
Enter the Spike mass by ‘Spike Mass’ enter, mass value
Tare the balance
Add the sample to the crucible and note the sample mass
Enter the sample mass electronically (F5) or manual (F1)
Place the prepared crucible (benzoic acid tablet with sample) in the lid assembly, inside the Vessel, close the Vessel and insert it in to the well.
When using MANUAL FILLING, fill the vessel with oxygen BEFORE inserting it into the well.
Enter the SID, e.g. 001
Close the Lid of the Calorimeter
The CAL3K Calorimeter will now perform some standard checks and if all is okay, it will begin with the “Initial Phase”, “Fire”, “Main” phase and then indicate that the determination has been completed.

Once the determination is complete, the result will display the calculated calorific value of the sample. The calorimeter will automatically take the end result, minus the spike energy and present the final result of your sample.

ENTER “SPIKE MASS”: