Ensuring that your test instrument provides accurate measurements on an on-going basis is strongly recommended.The Calibration Check card is a handy portable device that you can keep with your test instrument(s) to verify the continuity and insulation resistance has not drifted over a period of time.The range of known source fixed resistances built within the card enables you to verify the readings of your test instrument(s) against the manufacturer’s specification quickly and accurately.Such a flexible device simplifies the verification process and reduces the necessity for sending test instrument(s) off for calibration.