Display Standards

Use the Geochem Import > Standards > Display Standards menu option (CHSTNREP GX) to create a graphical standards report from a standards database.

Display Standards dialog options

Standards database	The name of the database that accumulates standards results from each assay batch.
Channels to report	"All ASSAY channels" – all channels in the current database that are members of the ASSAY class will be reported "Displayed ASSAY channels" – only channels displayed in the current database that are member of the ASSAY class will be reported. "All channels" – all channels in the current database will be reported "Displayed channels" – all numeric channels displayed in the current database will be reported "Select ASSAY channels from list" -- select channels from a two-panel selection list.
Tolerance selection	Select one of the following options: Use Channel Values The acceptable range is taken from the attributes for each individual channel. The "Standard Min" and Standard Max" values are used. If either of these values is not specified, then the behaviour reverts to "Default Error tolerance" below. Default Error tolerance The error tolerance is based on a multiple of the statistical standard deviation of all values in the standard element; the value is specified below in "Default error tolerance".
Default error tolerance (std.dev.)	The error tolerance bars will be displayed for each element reported, when "Default error tolerance" is selected in the "Tolerance Selection" above. The tolerance is specified as a multiple of the statistical standard deviation of all values in the standard element. New assays that lie outside the tolerance are indicated by a red circle. The default value is 2.0, which means the acceptable range is ± 2 standard deviations from the mean.

Application Notes

Standard samples are taken from a prepared company standard, which has a known concentration of various elements and compounds of interest. Each company standard must have a standard ID or name (such as "A123-5") that will be used to reference the standard. The standards are given a sample number and added at random to every batch of survey samples that are sent to a lab for assay. The lab performing the assay should have no idea which samples in a batch are standards. The name of the standard should be recorded in a "Standard" channel of the field database. When the field database is merged with the assay database, the standards can be identified by the entry in the standard channel, which will be blank for survey assays and will contain the standard ID for standard samples.

The CHSTND GX will go through a lab assay database (after merging with the field database) and extract all standard samples. The "Standard" must be blank for all samples in an assay batch that are not standards. For each standard sample in the assay database, the sample assay results will be removed and added to the end of a standards database. The results of each standard ID are stored in a separate database, which will have the name of the standard. For example, standards "A123-5" will be stored in database "A123-5.gdb".

Once a standards database exists, the CHSTNREP GX will display a report of the standard results. The report graphically displays the standard results for each element in chronological order. The last batch added to the standards database is displayed as colour dots right of a vertical line – green for acceptable, red for outside of the tolerance specification. Historical samples before the last batch will be limited to a maximum of 50 elements to give a visual indication of the expected distribution of samples, although all elements are used in calculating the standard deviation.

With the Standards Report as the active map, and the View of interest selected in the Map Manager Tool, use the Shadow Cursor Tool from the toolbar to dynamically link to samples in the Standards database. Alternatively, click a sample in the database to see the corresponding point in the report.