48
Reference Manual
00809-0700-4001, Rev AA
Operation and Maintenance
May 2017
Operation and Maintenance
5.4.2
Determining calibration frequency
Calibration frequency can vary greatly depending on the application, performance requirements, and
process conditions. Use the following procedure to determine calibration frequency that meets the
needs of your application.
1. Determine the performance required for your application.
2. Determine the operating conditions.
3. Calculate the Total Probable Error (TPE).
4. Calculate the stability per month.
5. Calculate the calibration frequency.
Sample calculation
Step 1: Determine the performance required for your application.
Step 2: Determine the operating conditions.
Step 3: Calculate total probable error (TPE).
Step 4: Calculate the stability per month.
Step 5: Calculate calibration frequency.
5.5
Trim the pressure signal
5.5.1
Sensor trim overview
A sensor trim corrects the pressure offset and pressure range to match a pressure standard. The upper
sensor trim corrects the pressure range and the lower Sensor trim (zero trim) corrects the pressure
offset. An accurate pressure standard is required for full calibration. A zero trim can be performed if the
process is vented.
Required Performance:
0.50% of span
Transmitter:
Rosemount 3051P, Range 1 [URL = 30 psi (2,1 bar)]
Calibrated Span:
30 psi (2,1 bar)
Ambient Temperature Change:
± 50 °F (28 °C)
TPE =
= 0.303% of span
Where:
Reference Accuracy =
± 0.040% of span
Ambient Temperature Effect =
± (0.05% URL + 0.25% of span) per 50 °F = ± 0.3% of span
Static Pressure Effect =
0% (does not apply to in-line products)
ReferenceAccuracy
(
)
2
TemperatureEffect
(
)
2
StaticPressureEffect
(
)
2
+
+
Stability
0.200
URL
×
(
)
Span
---------------------------------------- % of span for 10 years
0.0017% of URL for 1 month
±
=
±
=
Cal. Freq.
Req. Performance TPE
–
(
)
Stability per Month
--------------------------------------------------------------------
0.5% 0.303%
–
(
)
0.0017%
--------------------------------------------
118
x
months
=
=
=
Summary of Contents for Rosemount 3051P
Page 2: ......
Page 8: ...6 Reference Manual 00809 0700 4001 Rev AA Contents May 2017 Contents ...
Page 12: ...2 Reference Manual 00809 0700 4001 Rev AA Introduction May 2017 Introduction ...
Page 36: ...26 Reference Manual 00809 0700 4001 Rev AA Configuration May 2017 Configuration ...
Page 74: ...64 Reference Manual 00809 0700 4001 Rev AA Troubleshooting May 2017 Troubleshooting ...
Page 109: ......