The unit will need to be sent in for re-calibration to ensure it provides accurate results and continues to work within specification. Please download and fill in the Gate Force booking in Form and send it in with your device to the address below. As soon as we receive your unit in, we will contact you using the details you provided on the form. Applied Measurements Ltd Microtronics Calibration Department 6 Mercury House Calleva Park Aldermaston Berkshire RG7 8PN.