Digital basal thermometer for natural family planning

With the Geratherm® basal digital, you can determine the fertile days and ovulation by measuring the body temperature every morning and correctly documenting it. It is important to measure the body temperature immediately after waking up and definitely before getting up.


Important documents

Display with lighting

Read the measured value reliably, even in the dark.


The thermometer can be completely submerged under water for a short time and can also be washed under running water, for example.

Switchable °C and °F

This thermometer can be switched between degrees Celsius and Fahrenheit.

Technical Data

Measuring range 32,00 °C to 43,99 °C
Measurement accuracy +0,1 °C / - 0,1 °C in the range of 32,00 °C to 43,99 °C
Intended purpose Digital basal thermometer for cycle control
Measuring locations vaginal, rectal, oral, axillar
Storage conditions -25 °C to 70 °C
Please refer to the instructions for use for full technical data.

Questions and answers

Yes, the Geratherm® basal digital can be switched between Celsius and Fahrenheit.


Yes, the battery can be changed.

Caution: Keep the thermometer and batteries away from small children. If the battery is swallowed, contact a hospital immediately. Do not throw the battery into fire, it may explode.

Wipe the probe head with a solution of mild soapy water and cold water. Disinfect the thermometer by wiping the sensor and the lower section of the housing with a cloth previously dipped in alcohol (recommendation: isopropyl alcohol 70%). Do not boil the thermometer and do not clean it in the autoclave.

The Geratherm® basal digital is not waterproof.

The Geratherm® basal digital complies with IP 22, and is therefore protected against solid foreign bodies with a diameter of 12.5 mm and more and against water dripping at an angle of up to 15°.

At the top of the chart are the days of your cycle from 1 to 42, you can add more if
conducive. Above each day of the cycle write its date. The vertical temperatures are 35 °C
applied up to 38 °C. Draw your temperature with a dot. Mark the days when you
had sexual intercourse.

1 to 2 days after ovulation (ovulation), the basal body temperature rises by 0.2 to 0.5 °C and remains at this high level until beginning of the next cycle. (Right before the day of ovulation, a drop of about 0.1°C can often be observed.) In the event that ovulation has occurred if the temperature rise should have occurred within 48 hours. When you are about 3 Once you have filled out the tables, you will receive an ovulation chart and you will recognize your individual fertility chart.