water heater

LOSS FACTOR FOR LIQUID WATER

Fig. 1 By using Deby formula, the loss factor e" at 2.45 GHz are extrapolated from experimental values at 3 GHz, [11], [12]. Fig. 1 shows a loss factor variation of about one order of magnitude in the temperature range 0 < T < 100° C.	e"
		T °C Temperature dependence of the loss factor at 2.45 GHz

Table 1
This table shows the temperature variation of loss factor at 2.45 GHz with its fitted values.
A good fit to these data in the temperature range 25 < T < 75° C is given by the equation :

e" ~ 230 / T

T.° C

0
5
10
15
20
25
30
35
40
50
60
70
80
90
100

e"

20.7
17.2
14.7
12.6
10.8
8.9
7.7
6.7
6
4.5
3.6
2.8
2.3
1.9
1.6

230/T

46
23
15.3
11.5
9.2
7.6
6.5
5.7
4.6
3.8
3.2
2.8
2.5
2.3

T.° C	0	5	10	15	20	25	30	35	40	50	60	70	80	90	100
e"	20.7	17.2	14.7	12.6	10.8	8.9	7.7	6.7	6	4.5	3.6	2.8	2.3	1.9	1.6
230/T		46	23	15.3	11.5	9.2	7.6	6.5	5.7	4.6	3.8	3.2	2.8	2.5	2.3

However the fit does not hold in the temperature range 75 < T < 100° C, nor does it hold if the temperature of water is below ambiant temperature.

Table 2
In the temperature range 75 < T < 100° C the fit can be written as: e" ~ 190 / T

T.° C

70
80
90
100

e"

2.8
2.3
1.9
1.6

190/T

2.7
2.4
2.1
1.9