8
IM100CZ08-E9
6. CORRECTION
6.1 Correcting Indication Error due to the
Operating
Temperature
The pressure indication error caused by the difference between the
pressure sensor’s calibration temperature and the operating
temperature can be adjusted using the converter’s (CT-300E,
PCT-300E, PG500 and REX-PG410) gain setting. The pressure
indicator error [pressure sensor output (sensitivity) temperature
affect] is within a “span of ±0.2 %/10 ºC,” but the temperature affect
can be corrected if necessary.
Correction procedure
1.
The rated output after the correction is calculated from the
following correction equation and correction factor.
e
1
= [1 + Correction factor
×
(T
−
Calibration temp.)]
×
e
0
e
0
: Rated output of the resin pressure sensor
e
1
: Rated output after the correction
T: Operating
temperature
Correction factor: Refer to below
(
The correction factor is the actual value and not the warranted value.
)
Correction factor:
Diaphragm material
Calibration
temperature
(
°
C)
Correction factor
SUS630 150
+
0.13
×
10
−
3
SUS630
+
Kanigen plate
150
+
0.13
×
10
−
3
HASTELLOY C
150
Please contact RKC sale
office or the agent.
HASTELLOYC
+
Kanigen plate
250
SUPRON 250
+
0.10
×
10
−
3
2.
Set the value calculated in "
1.
" to the gain setting portion of the
converter (CT-300: Rated output setter, PCT-300: Gain setter,
PG500/REX-PG410: Gain setting parameter).
Example:
When the e
0
=
1.500 SUS630
diaphragm material’s pressure
sensor is used at 230
°
C.
e
1
= [1 + 0.13
×
10
-3
×
(230
−
150)]
×
1.500
e
1
= 1.516
Set 1.516 to the gain setting portion of the converter.
6.2 Correcting Indication Error due to the
Connection Cable Length
RKC Instrument’s resin pressure sensor is calibrated for the
standard cable length (5 m). Therefore, if the total length of the
pressure sensor connection cable connected to the intrinsically safe
circuit and non-intrinsically safe circuit side is other than 5 m, the
resin pressure sensor indication value can be corrected using the
converter’s gain setting.
Correction procedure
1.
The rated output after the correction is calculated from the
following correction equation and correction factor.
e
1
’
= e
0
’/[1 + K
×
(L
−
5)]
e
0
’: Rated output of the resin pressure sensor
e
1
’: Rated output after the correction
K (Correction factor):
1.96
×
10
-4
/m (Standard specification type)
1.40
×
10
-4
/m (Explosionproof specification type)
L:
Cable total length (m)
[However, when using RKC Instrument’s standard cable.]
2.
Set the value calculated in "
1.
" to the gain setting portion of the
converter (CT-300: Rated output setter, PCT-300: Gain setter,
PG500/REX-PG410: Gain setting parameter).
Example:
Cable total length (L)
=
10 m
Rated output of the resin pressure sensor (e
0
’)
=
1.500
e
1
’
= 1.500/[1 + 1.96
×
10
-4
×
(10
−
5)]
e
1
’ = 1.499
Set 1.499 to the gain setting portion of the converter.
6.3 Correcting Indication Error when the
Cable of Another Company is Used
The nominal cross-sectional area of our cable conductor is 0.5 mm
2
.
If using a cable from another company, the resin pressure sensor’s
indication value can be corrected by correcting the gain setting of
the converter (CT-300E, PCT-300E, PG500 and REX-PG410).
Correction procedure
1.
The rated output after the correction is calculated from the
following correction equation and correction factor.
e
1
’ = e
0
’/[1 + 0.5/S
×
K
×
(L
−
5)]
e
0
’: Rated output of the resin pressure sensor
e
1
’: Rated output after the correction
S: Conductor nominal cross-sectional area (mm
2
)
K (Correction factor):
1.96
×
10
-4
/m (Standard specification type)
1.40
×
10
-4
/m (Explosionproof specification type)
L:
Cable total length (m)
2.
Set the value calculated in "
1.
" to the gain setting portion of the
converter (CT-300: Rated output setter, PCT-300: Gain setter,
PG500/REX-PG410: Gain setting parameter).
Example:
Cable total length (L)
=
10 m
Conductor nominal cross-sectional area (S)
=
0.75 mm
2
Rated output of the resin pressure sensor (e
0
’)
=
1.500 mV/V
e
1
’ = 1.500/[1 + 0.5/0.75
×
1.96
×
10
-4
×
(10
−
5)]
e
1
’ = 1.499
Set 1.499 to the gain setting portion of the converter.
When anti-explosion specifications are required, use a
cable with an allowable capacitance between the cable
wires of 0.1
μ
F or less and an allowable inductance of
0.6 mH or less.
The allowable inductance could be exceeded if the cable is
wound, so do not wind the cable when using it.
6.4 Correcting Indication Error due to the
Safety
Barrier
A pressure indication error caused by the dispersion of our RZB-001
internal resistance value is within about 1 % of span. However, when
this error needs to be lessened further, make the correction, it
necessary. For this correction, the barrier correction factor B is used.
No correction is required when the barrier correction factor B is
“1.000.”
The barrier correction factor B is described on the
nameplate of the RZB-001.
Correction procedure
1.
The rated output after the correction is calculated from the
following correction equation and correction factor.
e
1
’’
= B
×
e
0
’’
e
0
’’: Rated output of the resin pressure sensor
e
1
’’: Rated output after the correction
B: Barrier correction factor
2.
Set the value calculated in "
1.
" to the gain setting portion of the
converter (CT-300: Rated output setter, PCT-300: Gain setter,
PG500/REX-PG410: Gain setting parameter).
Example:
Barrier correction factor (B)
=
1.001
Rated output of the resin pressure sensor
(
e
0
’’)
=
1.500 mV/V
Rated output after the correction
=
e
1
’’
e
1
’’
= 1.001
×
1.500
e
1
’’ = 1.502
Set 1.502 to the gain setting portion of the converter.