Yokogawa GD40 Gas Density Detector User Manual
Page 67
<5. DENSITY / PARAMETER SETTING>
5-12
IM 11T3E1-01E
(3) Entries for Calorie and Concentration Measurement
Measuring the calorific value (or concentration) requires the density to be correlated with the
calorific value (or concentration) by a linear equation (linear proportion).
Therefore, use the gas calorie meter in order to measure the calorific value as accurately as pos-
sible.
The relationship must be given by Y=aX+b, where Y is the calorific value (MJ/m
3
) and X is the
density (kg/m
3
).
l
Example of Entries for Calorie Measurement
Assuming the relationship is given by “calorific value = 58 × density + 6 (MJ/m
3
)”, the density
ranges from 0.5 to 0.7 kg/m
3
while the calorific value ranges from 35 to 46.6 MJ/m
3
.
The entries for the [*CALRY] parameter (see Figure 5.4) therefore are:
*Z_CAL: 35
*S_CAL: 46.6
*Z_CL.D: 0.5
*S_CL.D: 0.7
l
Example of Entries for Concentration Measurement
Assume we measure the concentration of hydrogen mixed with nitrogen and the relationship
is given by:
D = aX +b
where,
D=density of gas being measured (hydrogen: 0.0899 kg/m
3
; nitrogen: 1.2504 kg/m
3
),
and
X=volume percent (vol %) of hydrogen gas,
then the equation above is calculated as:
D= (0.0899-1.2504)(X/100) + 1.2504
= -1.1605(X/100) + 1.2504
N
2
H
2
X
(1-X)
Density
(D)
0
100
Volume percent (VOL%)
F0504.ai
1.2504
0.0899
The entries for the [*CONCT] parameter (see Figure 5.4) therefore are:
*Z_CON: 0
*S_CON: 100
*Z_CN.D: 1.2504
*S_CN.D: 0.0899