## First tests

I painted the end of a borosilicate test tube in black and want to know if the IR thermometter can measure the temperature inside.

Result: With hot water inside the temperature measured on the black end is slightly hotter than when measured on the side of the tube. Test with hotter water temperature confirm it

Tube volume= 16.6 cm3

2.-

I fill up a test tube with water the cork has a small hole for a 1/8"TC linked to a temperature recorder. I introduce the tube inside the the coil making sure that the TC is not exposed to the coil's field.

• Would the temperature changes when the coil is powered? - I assume no temp. change.:

Only 16.6ml of water in the tube:

0' temp= 19C,30" temp=20C,1min temp=20C,1'30' temp=19C,2' teemp=20C,5'temp=20C

Conclusion no induction thermal effect on water. (expected)

​3.-

Same test tube with 16.6ml water with a small stainless tubing 1.5mmOD 6.4g 50mm long tube exposed to field

0' temp=20C,1' temp=21C,2' temp=23C,3' temp=24C,4' temp=26C,5'temp=27C,

6' temp=28C,7' temp=30C,8' tem=30C,9' temp=31C,10' temp=32C

After switching off and homogeneisation of water in the tube Temp 33C/34C

Conclusion ΔT=12C for 10' - Water has absorbed 16.6*12= 830J for 600"->1.38W

Q = m x Cp x ΔT
ΔT = Q ÷ m ÷ Cp
1.38W x 600s = 828J

Calculed temperature of rode ΔT:
828 ÷ 6.4g ÷ 0.466J/g°C = 277.6°C

Same test tube + 16.6cm3 of water with Rod of soft iron weight:5.5g TC/IR temp(C):

0' 27.0/28.1, 1' 42.1 /38, 2' 57.4/47.6, 3'70.6/57.0, 4'82.6/63.0,  5'91.5/83.3 6' 104.0/83.3

Conclusion:

Water has absorbed in 4' 16.6*55.6*4.18=3858J/240= 16.1W

How hot will 5.5g of Iron get in 240 seconds when heated with a 16.1W heater?

Formulae:
Q = m x Cp x ΔT
ΔT = Q ÷ m ÷ Cp

Gives a ΔT= 1,561 deg C without lost

Water has absorbed in 3' 16.6*38.5*4.18=2671.5J/180= 14.8W-> ΔT=1,076

Water has absorbed in 2' 16.6*38.5*4.18=2033.1J/120= 16.9W->ΔT=819.4

Water has absorbed in 1' 16.6*14.9*4.18=1033.9J/60= 17.2W->ΔT=417

Globally the temperature of the rod increase of about 400 deg.C per minute!

Conclusion: Soft iron seems ideal to be used for heating the Ni powder because its hight  calorific capacity when heated by induction and in addition it becomes easily magnetized so it can attract the powder during the charging of the fuel in a tube.

Soft iron tubing could even be better if the fuel is charged inside,but I can't find so far any such tubing on internet.