Thermometer to see ovulation, is required to continuously monitor the basal body temperature, usually after ovulation basal body temperature will rise than the pre-ovulation temperature of 0.3 ~ 0.5 ℃ or so, can be through the rise in body temperature to determine the ovulation period. If a woman is able to ovulate normally, the ovary will form the corpus luteum after ovulation, and the progesterone secreted by the corpus luteum will increase the basal body temperature by 0.3-0.5℃. Therefore, the basal body temperature rises about 1 to 2 days after ovulation and continues to rise until the period before menstruation. Although it is easy to determine the day of ovulation by measuring the body temperature, it requires strict adherence over a long period of time, and external and internal factors can also affect the body temperature, so try to choose to measure the body temperature in the morning after waking up, and then record it. So to measure the basal body temperature to press the ovulation period is not accurate, if you want to clarify the day of ovulation can color ultrasound to monitor the follicle development, which is more accurate.