Evaluate for leaks in the system. You can do this by wrapping the cuff around itself and inflating it as high as it will go. Be sure the valve is completely closed and then watch the needle. It should not move. If it does, there may be a leak in the tubing, gauge or inflation bulb.
Check the needle position. Before inflating the cuff, the needle should be resting directly over the zero on the gauge. It should also return to zero after you deflate the cuff.
Calibrate annually. Blood pressure sphygmomanometers should be verified against a well-maintained mercury model. Connecting the mercury gauge and the aneroid gauge to each side of a plastic T. Attaching an inflation bulb to the bottom of the T. Pump the sphygmomanometers up to 300 mmHg and then slowly release the air. Periodically stop the deflation and read the gauges. If all the readings come within 2 to 3 mmHg of each other the cuff is appropriate for clinical use.
Inspect the cuff prior to each use. There should be no obvious damage to the cuff. You should look over the entire assembly, ensuring that the Velcro is firmly attached to the cuff, as well as making sure there are no cracks in the tubing or gauge cover.