The recommended service life of the height correction units (HCU) for these devices as well as earlier generation FMS and ADInstruments' human non-invasive blood pressure units is three years from the date of purchase. After this time, the correction value provided by the HCU will no longer be reliable, and the purchase of a replacement is recommended.
If you have any questions about the above, please contact your local ADInstruments Support Team for further assistance.