To control the usefulness of test strips, used for the analysis of human/animal body fluids e.g. blood glucose, a strip is measured to give a control reference value to be used in measuring further test strips
Test strips to control the usefulness of analysis (1), and the like, comprises initially, a reference value measurement takes a standard reference value at a reference control agent (4) as a standardized reference value for the control parameter. To control the usefulness of analysis test strips, and the like, the control parameter of the new test strip is determined as a control value to give a quotient with the first standard reference value as a control quotient. Any deviation between the control quotient and the first reference quotient is measured, and the test strip is rejected if the difference is outside a given tolerance range. The deviation is registered by a relative difference between the control quotient and the first reference quotient, or the actual difference. The new test strip is rejected if the control quotient is smaller than the first reference quotient by a given percentage or a given difference value. The tolerance range is specific to the actual charge of the test strip. The initial test strip and the further test strip are taken from the same package or dispenser, within a long-life packing, where they are each protected by separate wrappings. The test is made when a new package is used, when the first test strip is taken from the pack or on opening a long-life packing. The test stages are repeated if it is shown by the control measurement that test readings or the values measured by an analysis apparatus would be potentially affected. When a given deviation is noted, the control value for the second strip is taken as a new control reference value to give a new reference quotient for the control of further test strips. A new reference quotient is formed if the control quotient is greater than the reference quotient by more than a set threshold value, related to the actual charge of the test strip. One or more of the test stages can be automated. The reference control agent gives a higher measured value for the control parameter. The test strip has a test field (3) and a reference control agent for the measurement of the control reference value or control value. The control parameter is an optical measured value and especially a remission value.
