[Q] Help An Accurate Basal Thermometer ±0.1 °F? Significant Digits vs. Tech Specs

[ecaush]

We've been temping for a few months and FertilityFriend stated we need a better thermometer. We had been using a Vicks thermometer we had in the house that went to 0.1 F on the display (significant digits).

Easy enough, we buy the Target Up&Up Basal thermometer which shows 0.01 on the display (significant digits). However, in the tech specs they say it is only ± 0.2 accuracy. WTF.

Upon looking at another thermometer I find this statement:

ASTM laboratory accuracy requirements for the thermometer only (not including a probe cover) in the display range of 96.8 °F to 102.2 °F (36 °C to 39 °C) for infrared thermometers is ± 0.4 °F (± 0.2 °C), whereas for mercury-in-glass and electronic thermometers, the requirement per ASTM Standards E 667-86 and E 1112-86 is ± 0.2 °F ( ± 0.1 °C).

All I want is a thermometer that actually accurate to ±0.1 °F, that way we can eliminate one variable from temping. My online searching has basically been fruitless at this point. Does anyone have recommendations?

 

[lighthouse4031]

@ecaush I think it's important to remember you don't necessarily need accuracy in your temping, just consistency. If your thermometer is consistently inaccurate that's fine. You don't need to know if your temp was really 97.1 vs 97.3 because you are not looking for an accurate temperature. You're looking to see a temp shift to indicate ovulation. So long as your thermometer isn't throwing out completely random wonky temps, it is ok to not be the most accurate.

Usually a thermometer that reads to the hundredths place is recommended (X.xx). But if I looked at all of my charts in only to the tenth degree id still see a shift.

 

[ecaush]

I checked a few medical supply companies and looked at their professional thermometers ($10 to $900) They all had the same ±0.2 °F accuracy in the specs. My conclusion is the temping website might wrong about accuracy required as they might have gotten the Celsius and Fahrenheit mistaken ±0.2 °F = ±0.1 °C. I just hope the thermometer I have is precise.

 

[marlow1]

@ecaush I have my eye on this one MPLUS Digital Basal Thermometer for next cycle if I need it. I didn't know they had accuracy stated in the specs, but after looking, this one says Accuracy ±0.05℉ (±0.05℃). I think what other people said are correct though, I wouldn't worry about accuracy as much as consistency.

 

[jamesuk]

@marlow1 I also have this one and it did take the whole 3 flippin weeks to get it!

It's neat though.

 

[jerry7]

@ecaush It's not currently available on Amazon, but this is the one I used: http://www.amazon.com/B-D-524560-Di...1410114783&sr=8-10&keywords=basal+thermometer

It only records to the tenth place, but I think for most people, that's all you would need. I also agree with WinningColors, as long as your thermometer is consistent, it doesn't necessarily need to be accurate. Are you able to detect ovulation on your charts? If not, you might try another thermometer in case that is the problem, but I'm guessing both the Vicks one you had, and your new one will both likely work. Also, not sure if it is relevant for you, but I had to temp vaginally, because I'm definitely a mouth breather (damn you, allergies!). That definitely made my temps more consistent. Anyway, good luck!

 

[lemoene]

@ecaush We use one of those ear thermometers - it's not listed as a basal thermometer and it only goes to one decimal, but it has been fine. I think as long as you can see a pattern you're good.