This guide describes the step-by-step process for creating and managing result acceptance criteria. Acceptance criteria, per ISO 17025 §7.7, define the acceptable limits for each method–element combination, so the application automatically checks measurements during data entry.
Before you begin, make sure that:
Each acceptance criterion is linked to a unique method + element combination. You cannot create two criteria for the same combination.
Go to the Acceptance Criteria page from the main menu. A table of existing criteria is displayed.
The visible table columns are:
| Column | Description |
|---|---|
| Criteria No. | Unique code (for example AC-YYYY-0001) |
| Lab Method | The analysis method |
| Element | The chemical element or parameter |
| Expected Value | The reference value |
| Lower Limit | Minimum acceptable limit |
| Upper Limit | Maximum acceptable limit |
| Uncertainty | Expanded uncertainty (±U) |
| Notes | Additional remarks |
There is also a hidden "Formula" column containing a mathematical calculation formula. You can show it from the column settings.
Click the "+" button on the toolbar to open the creation form.
Fill in the fields:
AC-YYYY-0001) or enter your own codeThe method + element combination must be unique. If a criterion already exists for the same combination, an error will be shown.
Define the acceptable measurement limits:
| Field | Meaning | Example |
|---|---|---|
| Expected Value | The reference value expected from the measurement | 7.00 |
| Lower Limit | The minimum acceptable value | 6.50 |
| Upper Limit | The maximum acceptable value | 7.50 |
| Uncertainty (±U) | The expanded measurement uncertainty | 0.15 |
Example: For the pH method with element Fe, if the expected value is 150 mg/kg, you can set a lower limit of 120, upper limit of 180 and uncertainty of ±8.
During measurement entry, values outside the limits are automatically flagged.
The "Formula" field (hidden column) allows defining a mathematical calculation formula. The formula uses the variable x representing the measurement value.
Supported operators:
| Operator | Meaning | Example |
|---|---|---|
+ | Addition | x + 10 |
- | Subtraction | x - 5 |
| Multiplication | x 2.497 |
/ | Division | x / 1000 |
( ) | Grouping | (x + 5) * 2 |
When needed: Use the formula when the final evaluated value is derived from a unit conversion or calculation on the measurement. For example, converting N to NO₃ is done with the formula x * 4.427.
If no calculation is needed, leave the field empty — the measurement value is used as-is.
You can narrow down the displayed criteria in two ways:
Type in the search field for quick text filtering.
Click the filter icon to open the filter panel with the following options:
| Filter | Type | Description |
|---|---|---|
| Lab Method | Select | Show criteria for a single method only |
| Element | Select | Show criteria for a single element only |
| Uncertainty (from) | Number | Minimum uncertainty |
| Uncertainty (to) | Number | Maximum uncertainty |
| Max Records | Number | Record limit for print/export (default: 200) |
The "Max Records" filter only affects printing and CSV export, not the table display.
Click the print icon on the toolbar. A PDF list is generated with:
Click the export icon to download a CSV file of the filtered criteria.
Both functions respect active filters and the max records limit.
Can I have two criteria for the same method + element combination?
No. Each method–element combination allows only one acceptance criterion. This ensures each measurement is checked against clear, unique limits.
When should I use a formula instead of manual limits?
The formula is useful when the final evaluated value is derived from a unit conversion or calculation. If the measurement is compared directly against the limits, leave the formula empty.
How does auto-numbering work?
If you leave the "Criteria No." field blank during creation, the application assigns the next available code (format AC-YYYY-NNNN). You can also enter your own code.
What happens when a measurement exceeds the limits?
During measurement entry (manual or from an instrument file), values outside the limits are automatically flagged. The import results display a table showing the exceedances.
Can I change the limits of an existing criterion?
Yes. Open the criterion for editing and modify the limit fields. Changes apply to future measurements — previously recorded measurements are not re-checked automatically.