Emerson Micro Motion SGM Series - Compressibility Method and Process Limits

Option Description Setup
Polling The meter polls an external de-
vice for % N2 data.
a. Set % N2 Source to Poll for External Value.
b. Set Polling Slot to an available slot.
c. Set Polling Control to Poll as Primary or Poll as Secondary.
d. Set External Device Tag to the HART tag of the % N2 meas-
urement device.
Digital communica-
tions
A host writes % N2 data to the
meter at appropriate intervals.
a. Set % N2 Source to Fixed Value or Digital Communications.
b. Perform the necessary host programming and communica-
tions setup to write % N2 data to the meter at appropriate
intervals.
Fixed value The configured fixed value is
used.
a. Set % N2 Source to Fixed Value or Digital Communications.
b. Set % N2 (Fixed) to the desired value, in % by volume.
8. If you set Compressibility Measurement Method to SGERG 88, set % H2 Source to the
method you will use to supply % H2 data, and perform the required setup.
Option
Description Setup
Polling The meter polls an external de-
vice for % H2 data.
a. Set % H2 Source to Poll for External Value.
b. Set Polling Slot to an available slot.
c. Set Polling Control to Poll as Primary or Poll as Secondary.
d. Set External Device Tag to the HART tag of the % H2 meas-
urement device.
Digital communica-
tions
A host writes % H2 data to the
meter at appropriate intervals.
a. Set % H2 Source to Fixed Value or Digital Communications.
b. Perform the necessary host programming and communica-
tions setup to write % H2 data to the meter at appropriate
intervals.
Fixed value The configured fixed value is
used.
a. Set % H2 Source to Fixed Value or Digital Communications.
b. Set % H2 (Fixed) to the desired value, in % by volume.
7.4.1 Compressibility Method and process limits
Each method for calculating compressibility has specific limits for line temperature, line
pressure, and other process variables. If your process goes outside the valid range,
compressibility will be reported as NaN (Not a Number). All process variables that require
compressibility will also be reported as NaN.
Specific gravity and molecular weight meters: Compressibility Method and valid ranges for
process variables
Table 8-2:
Compressibility
Method
Valid range
Temperature Pressure
Specific
gravity % CO2 % N2 % H2
AGA NX-19
−40 to
+115.556 °C
1.01325 to
345.751 BarA
0.55 to 1 0–15% 0–15% 0–15%
Configure process measurement using ProLink III
60 Micro Motion
®
Gas Specific Gravity Meters (SGM)