About liquid phytase

Our company has liquid phytase equipment, and has been used, but I do not know how to know the accuracy and uniformity of the addition amount, is the error of the equipment display credible? Thank you for your advice! Can you believe it? Or the purpose of his design will be wasted. Uniformity can be tested. -- Oh, we can try it ourselves-- We used it for a period of time, but found that sometimes it was not very accurate, so we stopped. Is there a test method? Please give me some advice!