I just went through this scene, I'll explain. I bought a dehumidifier (in the midst of the rainiest winter here maybe since The Gold Rush!). So, this thing is chugin' 1/2 the time. I also have not yet installed any kind of central heating.
In an effort to determine my house's conditions I've accumulated an assortment of thermometer/hygrometers. Some are just thermometers. In accordance with the maxim "a man with a watch knows what time it is, a man with two watches is never sure" I've always wondered which if any of my thermometers is accurate. Same now with the hygrometers.
So, I found a deal on ebay being 5 Acurite 01083M thermometer/hygrometers. The manufacturer recommends using high quality AAA's in them (a pair). I have tended to use rechargeable Eneloops because they are cheaper in the long run and won't leak and ruin your devices.
The Acurite's support calibration, but when you change batteries you have to recalibrate. If I keep records I can recalibrate without difficulty, but the question remains did the device change?
Well, since the manufacturer seems insistent on high quality alkalines I shopped them last week. Some of the better ones say they are leak resistant or leak proof. They claim they have a stainless steel jacket integrated into the design that prevents the leakage of sulphates. Then there are lithium AAA's, but chargeable and otherwise. I haven't investigated the rechargeable lithium AAA's figure they're probably even more expensive than the non-rechargeables. Lithium AAAs are said to be leak proof because of the chemistry, they don't build up internal pressure like the alkalines, a big plus, I figure. They aren't cheap but I only need 10 for the Acurites and I ordered a package of a dozen Energizer Ultimate Lithium AAA's, should be here in 4 days.
Meantime, I have in my Amazon cart a
48 pack of ACDelco alkalines, 24 AA and 24 AAA. They are relatively inexpensive compared to the top name brands but they claim to be leak proof, or pretty much because of the stainless steel internal structure. I saw one review that complained about them leaking but that's nothing like the complaints I saw for most other alkaline cells.
BTW, I'm running a test right now with almost all my thermometer/hygrometers in a pan covered with Saran Wrap and a little wet salt in a bottle cap to control the humidity to 75%. I'm writing down data every few hours. I'm finding that only my 2 Yolink thermo/hygrometers (that I normally keep in my freezer and refrigerator, they transmit wifi data to my cell phones via a hub at my router) are close to accurate. Well, I have 3 similar devices I bought off Ebay that use a LR44 cell that look to be quite accurate as well, who knew? I've had them for years not knowing how accurate they were. But I have no way of getting a control for temperature, I guess, unless I buy an expensive instrument. The salt test for hygrometers is pretty easy and cheap and should produce data for calibration, but for a thermometer AFAIK you need one you know to be accurate. I'm developing some confidence in some but I can't swear by any of mine. Theoretically, all mine, even the ones that agree pretty closely, could be wrong. Yes, there's the ice water test, which works on some thermometers and I've done them, but none of those strike me as dependable as a benchmark to use against the others. And they may be right at 32F but not right at, say, 70F.