GE MG-101, User Manual

Page: 26 / 34

Appendix A. Supplemental Information
18 MG-101 User’s Manual
A.2 Typical Examples
The following examples show typical calculations based on the equations presented on the previous page.
A.2.1 Example 1
Data Table 2
is provided with the MG-101 to enable you to use the field calibration system to check sensor probe
calibration without calculating the value of p
w
.
Data Table 2
was compiled by calculating p
w
and thus, the dew/frost
point temperature by Equation 2 on the previous page. To use Data Table 2 , set the rotameters per the columns headed
“Dry Gas Setting” and either “High Wet Gas Setting” or “Low Wet Gas Setting.” Moving horizontally across the table,
read the generated dew/frost point temperature under the appropriate temperature reading.
Note:
The term “ Flowmeter” used in the data tables and is equivalent to the word “rotameter” used in this manual.
A.2.2 Example 2
To determine generated dew/frost point temperatures other than those listed in
Data Table 2
, Equation 2 on the previous
page must be used, as shown in the following example. If,
Dry Gas first dilution flowmeter setting F
d1
= 4,500 cc/min
Dry Gas second dilution flowmeter setting F
d
= 4,500 cc/min
Wet Gas flowmeter setting = 20 cc/min F
w1
= 140 cc/min
Wet Gas diluted flowmeter setting F
w
= 347 cc/min
Thermometer reading T = 20°C
and, P
s
= 17.535 mm Hg at 20°C (from Table 1 on page 19 ),
Then,
(3)
(4)
And, Pw = 0.0375 mm Hg, which is equivalent to a dew/frost point temperature of 48°C (by interpolation).
A.3 Vapor Pressure and Calibration Tables
Table 1 on page 19 is the vapor pressure of water as a function of temperature.
IMPORTANT:
Two tables not included in this manual, Data Tables 2 and 3 , are sets of calibrations generated at the
factory for each MG-101. These tables are supplied with the unit, and you must use these tables to
operate the MG-101. Since each table is specific to your instrument, you cannot use tables from another
unit. If you lose these tables, contact the factory and duplicates will be provided.
P
w
F
w
F
w
F
d
+
-------------------
 
 
  F
w1
F
w1
F
d1
+
-------------------------
 
 
 
P
s
=
Pw
347cc min
⁄
347cc min
⁄
4500cc min
⁄
+
-------------------------------------------------------------------
 
 
140cc min
⁄
140cc min
⁄
4500cc min
⁄
+
-------------------------------------------------------------------
 
 
17.353mmHg
( ) ⋅
=