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Ovulation Basal Body Thermometer Instructions

Basal Body Digital Thermometer Instructions

This post helps answer what is a basal body thermometer, how do you use a basal body thermometer & How using a BBT can help detect pregnancy or ovulation on your BBT chart.

A basal body thermometer can take the guesswork out of pinpointing when you’re ovulating. Knowing when you are most fertile helps increase your chances of getting pregnant fast.

We offer Ovulation thermometers in all our Fertility Home Test Kits along with ovulation tests and pregnancy tests.

Please read the instructions carefully before using the thermometer for the first  time

The best basal thermometer in Australia
When charting your Basal Body Temperature (BBT) take the guesswork out of pinpointing when you’re ovulating. Know when you’re the most fertile with our affordable and easy-to-use basal ovulation thermometer.

Instructions for our basal body thermometer

Before using, please disinfect the probe at first.

To switch on, press the ON/OFF button next to the display; a short beep will sound, indicating that the basal body thermometer (BBT) is operational. At the same time, the thermometer runs a self-check test, during which all the digital segments appear on the LCD.

When the letters ‘Lo’ and a flashing ‘C’ or ‘F’ display, the basal body thermometer is now ready for use. If the ambient temperature is below 32 C or 89.6 F, then ‘Lo C’ or ‘Lo F’ will appear on the LCD and if it is more than 43 C or 109.4 F, then ‘HI C’ or ‘HI F’ will appear on the LCD.

During the reading, the current temperature is displayed continuously and the ‘C’ or ‘F’ symbol flashes. The measurement is completed when a constant temperature value has been reached. The temperature value is considered constant when the temperature rises less than 0.1 C within 16 seconds.

As soon as the constant temperature value is reached, a beep will sound four times, and the ‘C’ or ‘F’ symbol will stop flashing. The highest temperature measured appears on the LCD. However, please note that this thermometer is a maximum thermometer, i.e. the displayed temperature can increase slightly if measurement continues after the beep. This is particularly the case with axillary measurements, should a temperature value be recorded which approximates the core body temperature. In this instance please note the description under ‘Methods of measuring temperature’.

When the measurement is completed and you have recorded your temperature, please switch the basal body ovulation thermometer off by pressing the ON/OFF button. After the temperature has been displayed, the thermometer will shut off automatically after 10 minutes.

When to take your basal temperature

  • Check your temperature as soon as you wake up and before you get out of bed.
  • Check your temperature at the same time each day.
  • Note any differences on your chart/app if your sleep was disturbed.
  • If you get less than 3 hours of consecutive sleep your temperature is considered inaccurate that day — make a note of this.

For more information on when to use the ovulation thermometer please read our blogs 

What type of thermometer for basal body temperature?

A BBT needs to be Accurate to 0.01 degrees Celsius, which will read as 36.50,36.51 and so on. if your ovulation thermometer is not accurate to a tenth of a degree you may be missing out on the slight changes in your basal temperature.

What other methods can be used to detect ovulation?

Ovulation can be detected in many ways. The symptoms of ovulation are often small and require careful monitoring.

Some methods used to detect ovulation include:
– Ovulation Tests
– Cervical Mucus
– Basal Body Temperature
– Ovulation Pains.
Check out our page dedicated to ovulation symptoms and how to track them.

Where to buy a good Basal thermometer?

We offer our great ovulation thermometers by themselves or in our of our value packs which include a large range of ovulation tests, pregnancy tests, conceive plus fertility lubricant and the best basal thermometer in Australia.

Our most popular pack is our Major Fertility Kit which includes
50 x Ovulation Strip Tests
10 x Pregnancy Strip Tests
1 x Ovulation Basal Thermometer


cheap ovulation thermometer
Our basal thermometers are accurate to two decimal places
Basal Body Thermometer
The best basal thermometer in Australia

Ovulation Thermometer & Memory Function

Switch the ovulation thermometer off, then press the ON/OFF button for about 2 seconds. The last measured value with ‘C’ or ‘F’ will appear automatically on the LCD. This display is visible as long as the ON/OFF button is held down. The reading is only over-written when a new temperature value is recorded.

Where do you put a basal body thermometer?

It is important to remember that the body temperature reading depends on the site where it is measured. For this reason, the measurement site must always be specified to ensure that a correct temperature reading is recorded.

Methods of Measuring BBT Temperature:

In the Mouth (oral)

There are different heat zones in the mouth. As a general rule, the oral temperature is 0.3 C to 0.8 C lower than the rectal temperature.

To ensure that the reading is as accurate as possible, place the thermometer tip to the left or right of the root of the tongue.

The Basal Body Thermometer tip must have constant contact with the tissue during the reading and be placed under the tongue in one of the two heat pockets at the back, keep the mouth closed during the reading and breathe evenly through the nose.

Do not eat or drink anything before the measurement. The usual measuring time is approximately 50 to 70 seconds.

In the Rectum (rectal)

This is the most accurate method from a medical point of view because it comes closest to the core body temperature.

The ovulation thermometer tip is inserted carefully into the rectum for a maximum of 2 cm. The usual measuring time is approximately 40 to 60 seconds.

Under the Arm (axillary)

Placing the basal thermometer in the armpit provides a measurement of surface temperature that can fluctuate by around 0.5 C to 1.5 C from rectal temperature readings in adults.

The usual measuring time for this method is approximately 80 to 120 seconds. It should be noted, however, that an exact reading cannot be obtained if, for example, the armpits have been allowed to cool.

If this is the case, we recommend extending the measuring time by around 5 minutes to obtain the most precise possible reading that corresponds as closely as possible to the core body temperature.

How to Change the Measuring Scale (only for switchable type)

To switch the display between C and F on the Basal Body Thermometer, turn the unit on. Press and hold the ON/OFF button for 2 seconds, the display will show another scale.

Cleaning and Disinfection

The best way to clean the thermometer tip is by applying a disinfectant (e.g. 70% ethyl alcohol) with a damp cloth.

Safety Precautions

  • Do not allow the Basal Body Thermometer to come into contact with hot water
  • Do not expose to high temperatures or direct sunlight
  • Do not drop the thermometer. It is neither shock-proof nor impact-resistant
  • Do not bend or open the device (except the battery compartment)
  • Do not clean with thinners, petrol or benzenel
  • Only clean with water or disinfectant
  • Do not immerse the waterproof thermometers underwater 15cm for longer than 30 minutes
  • The thermometer contains small parts (battery, battery compartment) which can be swallowed by children.

For this reason, do not leave the thermometer unattended in the hands of children

  • Avoid bending the thermometer tip
  • If the ambient temperature is over 35 C or 95 F, dip the thermometer tip in cold water for approx.

5 to 10 seconds before measuring the temperature

  • Persistent fever, in particular in children, has to be treated by a doctor- please get in touch with your doctor!

Battery Replacement for your Basal Body Thermometer

The battery is empty and needs replacing when the “ “ or “ “ battery symbol appears on the right of the LCD.

Remove the battery cover and replace it with a battery (preferably non-mercury) of the same type.

Product Disposal

Please ensure environmental protection of your Basal Body Thermometer. Batteries do not belong in domestic waste. Please hand them in at the collection point or the municipal recycle material centre as special waste.

This symbol on products and/or accompanying documents means that consumed electronic products must not be mixed with conventional domestic waste.

Take these products to the corresponding collection points for correct treatment and recycling, where they will be accepted free of charge.

For more information on the closest collection point, please enquire with your local authorities.

Technical Data

Type: maximum thermometer

Measurement range: (32.00~ 43.00)°C/(89.60~109.40)°F

Measurement accuracy: +/- 0.10°C/0.20°F(35.50°C~42.00°C/95.90°F~107.60°F)


Ambient temperature during use: (5~35)°C, ≤80%RH

Battery Type: Alkaline manganese battery, type LR41, 1.5V, service life minimum 100 hours under continuous operation

Weight: Approx. 12g

Explanation of Symbols

The battery is empty – When a square is flashing in the bottom right-hand corner

Lo°C or Lo°F: Temperature under 32°C or 89.6°F

Hi°C or Hi°F: Temperature over 43°C or 109.4°F

Calibration Check

This ovulation basal thermometer is initially calibrated at the time of manufacture. If this thermometer is used according to the operation instruction, periodic re-adjustment is not required.

The calibration check has to be carried out immediately. If there are indications that the product does not keep the defined error limits or the calibration properties could have been affected by intervention or by any other means.

Please also observe any national statutory regulations. The calibration check can be carried out on your Basal Body Thermometer by competent authorities or by authorised service providers. A test instruction for calibration check can be provided to the relevant authorities and authorised services providers on request.

A basal body thermometer can help detect pregnancy or ovulation, Use an Ovulation thermometer to detect ovulation & get pregnant faster