Laboratory Concepts: Analysis and Setup

 

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Fundamental Concepts

 
              

 

Fundamental Concepts

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In this example, a quantity of graphite taken from a pencil will be tested for hardness at an ambient temperature of 23 deg C.

Laboratory Concept LabVantage Concept Example
Determine properties to be tested A Parameter is a variable that holds a data value.
Parameters can represent a property or condition to be tested.
Parameter Data Collected Entered Data
hardness Hardness of the graphite. 1.2478
temp Ambient temperature during testing. 23.1924
A Parameter List is a collection of Parameters, all having something in common, but each having its own rules for manipulating and displaying entered data.
Parameter List Parameter Rules for Data Manipulation and Display
scratch hardness hardness Transformation Rule
Calculation Rule
Display Format
Parameter Limit
temp Display Format
Specify how
results are calculated 		A Transformation Rule is a mathematical expression that can be applied to entered data. Any expression capable of being processed by LabVantage can be applied.

The resulting "Transformed Value" is used to evaluate Calculation Rules, Parameter Limits, and Specifications.
Parameter List Parameter Transformation Rule Entered Data Transformed Value
scratch hardness hardness Round to 3 dp 1.2478 1.248
temp Truncate to 3 dp 23.1924 23.192
A Calculation Rule is an expression that derives a Parameter value from one or more other input values using a logical or mathematical expression.

For example, the value of a Parameter can be the sum of two other Parameters, the product of another Parameter and a constant, and so on.

 We add another Parameter to this example only, solely for the sake of demonstrating how a Calculation Rule could be used.

Here, we apply a logical expression to derive a value for "grade" based on the hardness of the graphite.

Parameter List Parameter Calculation Rule Transformed Value Calculated Value
scratch hardness hardness (none) 1.248 (none)
grade If hardness > 1.3, then grade = 2B, otherwise grade = HB N/A HB
temp (none) 23.192 (none)
Specify how
data are displayed 		A Display Format defines how the data are displayed.
Parameter List Parameter Display Format Transformed Value Displayed Value
scratch hardness hardness Format to 2 dp 1.248 1.25
temp Format to 1 dp 23.392 23.4
Define limits for each Parameter (such as detection limits) A Parameter Limit specifies a numerical range against which test data are checked. When the test result falls within or outside the limit, a LabVantage Action can be executed (such as to send an email).
Each range is identified by a "Parameter Limit Type", which defines the condition of the Parameter if the result falls within that range (such as "pass" or "fail").
This is not intended to indicate the quality of the test result.
Parameter List Parameter Parameter Limit Transformed Value
scratch hardness hardness 1.2 = x = 1.5 1.248
temp (none) 23.392

where x = Transformed Value
A Limit Rule redefines the conditions defined in the Parameter Limit Type. If x = "pass", do nothing. Since x = 1.248, no action is taken.

If x = "fail" (such as x = 1.1), an email is sent to the Lab Manager.
Define limits to indicate Sample quality A Specification is a set of numerical ranges (or other criteria) and rules against which entered data are automatically checked to provide an indication of the "quality" of entered data.
Each range is identified by a Specification Limit Type, which defines the condition of the Parameter if the result falls within that range (such as "in spec" or "out of spec").
Item to be Tested Parameter List Parameter Specification Transformed Value
graphite scratch hardness hardness 1.2 = x = 1.45 1.248
temp (none) 23.392

where x = Transformed Value
A Specification Rule defines criteria that indicate overall quality of the Sample. If all data collected for the graphite = "in spec", the graphite being tested "passes".
If any data collected for the graphite = "out of spec", the graphite being tested "fails".
Identify laboratory instrument An Instrument defines the laboratory device used to collect data.
In order for raw data to be collected by a laboratory instrument and automatically transferred to LabVantage, the instrument and its interface driver must be defined.		 An RSA-2 Constant Strain Solids Analyzer is used to conduct the hardness test.
Certify Analyst An Analyst is a LabVantage User. Analysts must be certified to perform the analysis. In order to perform the hardness measurement, a User must be certified to enter data defined in the "scratch hardness" Parameter List.
Specify analytical method
or procedure 		A Test Method provides a complete set of instructions for conducting an analytical test, including any number of Parameter Lists (such as for Preparatory testing), Specifications, and other Test Methods. Using the previous examples, a "scratch hardness" Test Method could contain the "scratch hardness" Parameter List and the Specification.
You could also have a Test Method called "lead test" that contains a "scratch hardness" Test Method to test for hardness, and a "color" Test Method to test for blackness.