The condition of the instruments for BP measurement is too often neglected in common practice and should be a special responsibility of a designated staff member. This person should be sure to check the calibration of the manometers every 6 months or sooner if the arrow does not exactly point to the zero mark. This should be recorded on a calibration log. For the cuffs and stethoscope, their cleanliness and general working order can usually be determined by simple inspection. Those inspections should include the conditions of all tubings and fittings and a check of zero level. If the aneroid gauge does not calibrate to zero it will be sent back to the manufacturer to be recalibrated.