One bottle of high or low solution to test the accuracy of your meter. Control test should be performed:

• Monthly
• With each new vial of strips
• When you change batteries
• If you suspect the meter is malfunctioning

To perform a control test, apply a drop of control solution to the test strip instead of a drop of blood. Compare the test results to the control range ( usually printed on the side of the vial of strips.)
If the test results are inside the range printed on the vial, your meter is functioning correctly. If the results are outside the range, you should call the manufacturer of your meter immediately.