Geratherm Basal Mercury Free Thermometer - 1 ea

by Geratherm

Product Features

• Geratherm Thermometer with magnified optic case included for easy readability.
• Includes easy to follow instructions and tracking chart.
• Traditional shake down glass analog thermometer.
• As accurate as mercury thermometers.

Product Description

INDICATIONS: Basal non toxic/mercury Free thermometer with magnified optic case included for easy readability. Includes easy to follow instructions and tracking chart.

Product Details

• Item Weight: 1.1 ounces
• Shipping Weight: 5.8 pounds (View shipping rates and policies)
• ASIN: B0013NB6CY
• UPC: 614801200608
• Average Customer Review: 3.5 out of 5 stars  See all reviews (11 customer reviews)
• Amazon Best Sellers Rank: #33,156 in Health & Personal Care (See Top 100 in Health & Personal Care)

Customer Reviews

Most Helpful Customer Reviews

12 of 13 people found the following review helpful:

5.0 out of 5 stars Best substitute for Hg! More RELIABLE N ACCURATE than Digital, September 29, 2010

By 

Physicsmind "Physicswish" (CA United States) - See all my reviews

This review is from: Geratherm Basal Mercury Free Thermometer - 1 ea (Health and Beauty)

I had high hopes for this thermometer, after reading a medical article comparing it with standard mercury (Hg) thermometers in a clinical trial. All the accuracy, but without the significant health risks if it breaks. Well, I still have an "old fashioned" Hg thermometer, in addition to an electronic probe and an ear device from a major manufacturer (for the home, not professional market).

When I purchased this, I compared it to the Hg thermometer, since I have one and I was curious about the new Hg substitute. First, I put them both under my tongue simultaneously. This one read about 2 degrees lower than the Hg standard. I thought that its larger size might have allowed air to get by my lips & cool it. I then did two back-to-back measurements; Geratherm, Hg; Geratherm, Hg. Four minutes each, all at rest, one immediately after the other, and always placing them in the same location. Both devices were "internally" consistent - that is the Hg gave the same temp both times, sequentially, as did the Geratherm. So far, so good. Consistency is necessary in a measuring instrument. HOWEVER, on both occasions the Geratherm now measured a full two (2) degrees HIGHER than the Hg! NOT good! I then checked my temp using the oral electronic probe; it was 0.2 degrees off from the Hg. I then used the ear probe (both ears) and surprisingly it, too, was actually very close to the Hg (0.2 degrees difference between the 2 ears; average 0.3 degrees off from Hg, just a bit lower otic (ear) than oral).

For this reason, I'm returning it, and I'm going to try another one. I suspect that it's a manufacturing defect explained by the construction of this thermometer - it's a glass tube within a second glass housing, and there's a paper scale behind the capillary tube containing the liquid. If that paper is not placed properly, the reading will be "off." The device's consistency suggests that the liquid expanded properly & consistently in response to my temp. My old Hg thermometer has the typical printing on the glass. Sure, that could be off, but those devices have been standardized over decades. And the good correlation with other devices (particularly the electronic probe, which I've calibrated against known standards - freezing & boiling water, & it's accurate) suggests that my old thermometer is the correct one.

Other comments - I didn't find it particularly worse than the old standard to "shake down;" each took the same # of shakes to return to baseline. I'd seen reviews elsewhere in which users had complained about this being difficult. Yes, if one has arthritis, neither this nor a mercury thermometer are easy to use, and you're probably best off with a high rated electronic probe. Also, the outer glass housing is much larger (about 3X) the size of the Hg thermometer, which made it a little more cumbersome to hold under the tongue, but not impossible. Because of its size, I don't think it would be particularly good for a child under about age 7-8.

Hope this helps other users. I am concerned about this, especially as a medical professional, because not everyone has a mercury thermometer to compare against. This 2 degree difference could mean a LOT if you're using this in a "sick" situation (e.g. deciding if your older child can go to school or not). I plan on contacting the manufacturer about this.

7 of 7 people found the following review helpful:

5.0 out of 5 stars Great Thermometer, January 15, 2010

By 

Paula - See all my reviews
(REAL NAME)   

I have used a glass basal thermometer for years now and I really like this particular one. The one I had previously was skinnier. I like this one because it is a little bigger, though I don't think it really matters. You cannot find a basal thermometer in the stores. I looked at a glass thermometer the other day in the store and it is not broken down into tenths, which I think is important. It takes only five minutes to get a temp reading and is very accuate, unlike the basal digital thermometer.

4 of 4 people found the following review helpful:

5.0 out of 5 stars An affordable reference thermometer for sous vide!, June 17, 2011

By 

Robert Jueneman (Taos, NM) - See all my reviews
(REAL NAME)   

This review is from: Geratherm Basal Mercury Free Thermometer - 1 ea (Health and Beauty)

My wife and I are well past the age where we need an ovulation thermometer, but I've been cooking sous vide for the last four years, and an accurate thermometer that can be used to calibrate the sous vide water bath is absolutely essential.

I've compared my Geratherm to my nearly $400 Traceable 4000 reference thermometer made by Control Company, which is calibrated to NIST standards and accurate within 0.05C. By using the magnifying sleeve on the Geratherm, you can visually interpolate to 0.02F, and the Geratherm agreed with the Traceable 4000 EXACTLY.

You can use the Geratherm to calibrate your other kitchen thermometers, say at 100F. That will be far more accurate and linear than trying to play kitchen physicist and rig up a proper ice-water bath, or even worse a boiling water bath.

For the low price of this thermometer compared to other decent thermometers, I would buy two and compare them, just to be doubly-sure. And then calibrate all your other thermometers as well -- I have seen some that were off by 5 degrees, even though they were supposed to be accurate to 0.1F!