Non-toxic glass thermometer for BBT charting.
The Mercury-Free Glass Basal Thermometer is a safe, accurate, environmentally-friendly alternative to a mercury basal thermometer designed specifically for Basal Body Temperature (BBT) charting.
This easy-to-use glass basal thermometer is ultra-accurate and certified to exceed ASTM standards—a most important feature for BBT charting.
This glass basal thermometer contains absolutely no mercury, using a safe, liquid alloy instead. Concerns about mercury have been featured prominently in the news, and many states are requiring that mercury-containing thermometers be recalled by manufacturers due to toxicity and related health hazards, particularly for pregnant and trying-to-conceive women.
For help making a basal thermometer purchase, read our Basal Body Thermometers Buyer’s Guide.
For bulk purchases for your clinic or health organization, please visit our Institutional Orders
The Mercury-Free Glass Basal Thermometer comes with:
- fertility charts
- detailed instructions on BBT charting
- a carrying/storage case with built-in magnifying lens
Marya –
Does what it is supposed to do — accurate and detailed temperature measurement!
Taking my basal morning temoerature, we conceived the first month. Hard to be more satisfied than that!
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Tenecia –
It’s a very accurate thermometer!
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Toni –
I am using this thermometer for testing my thyroid function using my basal temperature in the AM. It has large numbers and is very sensitive to variations in temperature. Sometimes the reading is a little hard to read because the line is very thin, but otherwise, it’s a great thermometer.
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Linda –
Got this to test my temperature with relation to thyroid problems. Pros: Easy to read, accurate Cons: I have to snap it 10 – 15 times to get it below 97 and another 10 – 15 times to get it to below 96 (as is recommended for thyroid problems). Don’t know if mine if defective but I snap it really hard and that’s what it takes.
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Elizabeth –
Seems like a great product. I love the protective/magnifying case that comes with it. It arrived yesterday and after using it for the first time, I was shaking it down, but I had left it in the protective case and when I shook it the wrong direction, it came flying out and hit the ground and shattered. I’ve just ordered a replacement…
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Lara –
I’ve been using this thermometer for over 2 months and like the performance. A lot of people seem to mention problems with the glass breaking, well, I’m not sure how toxic the plastics used in digital thermometers are, but I’ll take the risk of broken glass over the risk and instability of digitals any day. I am going to buy an extra backup one, just in case.
As far as ‘shaking down’ the temp. well, I never could get the hang of that, but someone on another website suggested putting it into the toe of a clean (lightweight) sock and spinning like a propeller. This works perfectly but you have to be careful because if it bangs against anything it could break.
I wait 5 minutes to make sure the temp has stabilized, and sterilize it with alcohol.
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Kami –
I used this thermometer to chart for 1.5 cycles. It broke halfway through this cycle. I really liked it because it doesn’t beep and wake my husband up. The thermometer is a little wide at the bottom where it goes in your mouth making it a little awkward to take temp with. The thermometer cracked where it goes from being narrow to wide. I wish it was narrower.
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Yuliya –
After doing my research and reading tons of reviews, opted to go with this thermometer instead of digital. Hoping to use for natural birth control at the moment, maybe for pregnancy down the line. Took a few tries the first day just to test for accuracy/ if the alloy even moves, after 3 tries I found the sweet spot in my mouth where it read most accurate. This is the first morning starting my charting, the temp read accurately to my knowledge. It took 5 min to measure
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E –
Ordered this to check for thyroid issues; it works great! Thanks!
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Joanna –
Great thermometer! Much more reliable then my past two digital ones! No battery to worry about. Super accurate!
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