Frost protection relies on an adequate rate of water application to the sensitive parts of plants. The system of calibration used here was developed for overhead frost protection systems on grapevines. Prepared with funding from NZ Wine and MAF SFF, this is still very much a draft that has been released for "beta-testing" on vineyards. Feedback is welcomed. In our climate, there can be significant air movement during frost events, and this movement can affect systems performance. We suggest you consider this when doing your calibrations; try to get equivalent conditions so your test is relevant. Overhead Frost Protection Calibration: A DRAFT Guide and Worksheet for vineyard performance checks.