Environment Parameter Tolerance Worksheet Features 
This drill-down worksheet provides a useful tool for evaluating measurement uncertainty for a given environment parameter.  The Tolerance Worksheet is activated by clicking the ID Number button to the left of the environment parameter name entered into the Environment Parameters table on the Environmental Factors Uncertainty Worksheet.  The Tolerance Worksheet is a tool for estimating uncertainty due to environmental or ancillary factors.  It can be used instead of entering data directly into the Environment Parameters table.  A set of procedures can be displayed on the right side of the Worksheet by selecting View Procedure on the menu. The procedures can be hidden by selecting Hide Procedure. 
 
The Tolerance Worksheet can be used to estimate two types of uncertainties: 1) uncertainty in an environmental/ancillary correction or 2) uncertainty due to environmental/ancillary variations.  The worksheet entry fields change slightly depending upon the uncertainty analysis option that is chosen.
 
Environmental Correction Uncertainty
When this analysis option is selected, the upper portion of the Worksheet provides Environment Parameter Data entry fields for the Parameter Name, Measurement Area, Measurement Units, Reading, Full Scale, and Range that help define the environment parameter of interest.  This portion of the worksheet is also used to develop a bias uncertainty in the environment parameter.  

The bottom half of the Worksheet contains the Correction Uncertainty data entry and display fields.  The Correction Uncertainty Section of the Worksheet is used to compute a correction value for the environment parameter of interest and to estimate the uncertainty in the correction.  The Bias Uncertainty is computed from user specified ± Limits and In-Tolerance Probability (i.e., the probability that the environment parameter bias is contained within the ± limits).  The Units for the ± Limits are selected from a drop-down list.  The ± Limits can be specified as a Fixed value, % of Reading, % of Scale, % of Range, or any combination of these quantities.

When the Environmental Correction Uncertainty is being estimated, some additional options appear at the bottom of the Tolerance Worksheet.  These options allow the user to add or subtract the Correction Uncertainty to the SU Measurements (i.e., subject parameter measurements) or the MTE Measurements (i.e., measuring parameter measurements).  The net sum of the Correction Uncertainties for all environment parameter considered is displayed in the Env Correction field on the Measurement Data Entry Worksheet for the Subject or Measuring Parameter.
 
Environmental Variation Uncertainty
When this analysis option is selected, the upper portion of the Tolerance Worksheet provides Environment Parameter Data entry fields for the Parameter Name, Measurement Area, Measurement Units, Nominal or Baseline, Full Scale, and Range that help define the environment parameter of interest.  This portion of the worksheet is also used to develop an uncertainty in the environmental variation.  

The bottom half of the Worksheet contains the Environmental Uncertainty data entry and display fields.  The Environmental Uncertainty Section of the Worksheet is used to compute the uncertainty due to environmental or ancillary variations. The Variation Uncertainty is computed from user specified ± Limits and Containment Probability (i.e., the probability that the environment parameter variation is contained within the ± limits).  The Units for the ± Limits are selected from a drop-down list.  The ± Limits can be specified as a Fixed value, % of Baseline, % of Scale, % of Range, or any combination of these quantities.