Vapor Calibration

  Values and screen shots in this topic are for a typical vapor calibration for pyridine.

When using the optional vapor generator, it must be calibrated for the type of vapor to be used. Associating the analysis data with a vapor generator calibration file allows the conversion of peak area data to volume data. The calibration can be performed either before or after performing the analysis. A single calibration file can be used with multiple analysis files.

  1. Go to File > Open > Sample information. Enter a calibration file name (.CAL). Click OK, then click Yes to confirm.
  2. Complete the remaining fields on the Sample Description window as needed.
  If the window displays in Basic presentation, click Advanced in the view selector drop-down at the bottom of the window.
  1. Select the Analysis Conditions tab. Click Insert, then select Vapor Calibration.

  1. Complete the window using these entries:
Selections Description

Calibration Gases [group box]

Select Helium. Enter a flow rate of 50 for each.
Reflux Temperatures [group box] Enter a minimum of 70 and maximum of 80.
Flask Temperatures [group box] Enter a minimum of 80 and maximum of 100.
Number of steps [text box] 5
Recording Options [group box] Select the signal. It is a good idea to select this option when using helium for the carrier gas. It improves the performance of automatic peak picking.
Zones [button]
Field Enter
TCD Detector

Block zone

100

Filament

175
Valve Zones

Cold trap

110

Analysis

110

Loop

110

Vapor generator

20
Vapor Generator

Reflux

20

Flask

20
Outputs [button] See Auxiliary Inputs and Outputs.
  1. Click OK to close the Set Temperature Zones window, then again to close the Vapor Calibration Experiment window.
  2. Click Save As, enter a file name, then click Close.
  3. Go to Unit [n] > Sample Analysis. Click Browse and select the sample file just created.
  4. Click Next three times to accept the values contained in this sample file. These values can be edited, however, no changes are needed for this example. Click Start.
  5. Use the other views of the Analysis window to observe the progress of the analysis.
  6. When the analysis completes, close the Analysis window.
  1. When the displayed sample temperature reaches the ambient temperature, open the furnace. Use gloves and remove the sample tube. These fields do not require editing; the Reflux and Flask temperatures entered on the Vapor Calibration Experiment window are used.
  2. To edit the calibration file, go to Options > Signal Calibration > New.
 

Use the cotton gloves provided in the accessory kit when handling heated surfaces. These cotton gloves are not intended to protect hands when heated surfaces are above 60 °C.

  1. Select Load Calibration Data and select the sample file for this calibration; the data contained in the file are automatically loaded.
  2. Access the Calculations document on the Micromeritics web page  (www.micromeritics.com) for information on calculating the volume of each vapor injection, then enter the values for each peak.
  3. Assess the plot, Goodness of Fit, and Coefficients to decide if the calibration file is acceptable. Use your laboratory’s standards to determine what level of linearity is acceptable. As a general guideline, use a calibration file with a very low value for Goodness of Fit (less than 1 to 2% of the signal), when 1st or 2nd Degree is specified.
  4. To delete any peaks that are outliers, highlight the peak data in the table and click Delete Peak. Evaluate the results when the degree is changed (select a different degree from the drop-down list).
  5. When satisfied with the calibration file, click Save then click Close.