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Cheap Chinese Calipers w/ Free delivery
- Thread starter Rata222
- Start date
- Joined
- Feb 13, 2017
- Messages
- 2,138
Thinking about battery life, one just has to ask how long they have been installed before they reached the market. On anything that has batteries included, I always assume the battery to be near dead when I get it. Although it has gotten better over the years, even "new" batteries still have a limited shelf life.
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- Joined
- Feb 13, 2017
- Messages
- 2,138
Thinking further on the subject, I would add another post rather than editing the one above.
From an electronicist's point of view, even small devices that have a "push button" off switch still draw a minute current in the off state. It is measureable only with a sensitive DMM, but is there none the less. Even a micro-amp, 1/1000 of a milli-amp which is 1/1000 of an amp will still run the battery down while in storage. The only way to interrupt this current is to break the copper connection to the battery. In the case of something as small as a caliper, removal of the battery is the only practical solution. At that point, limited shelf life comes into play. Most batteries will self discharge some small amount even in storage.
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From an electronicist's point of view, even small devices that have a "push button" off switch still draw a minute current in the off state. It is measureable only with a sensitive DMM, but is there none the less. Even a micro-amp, 1/1000 of a milli-amp which is 1/1000 of an amp will still run the battery down while in storage. The only way to interrupt this current is to break the copper connection to the battery. In the case of something as small as a caliper, removal of the battery is the only practical solution. At that point, limited shelf life comes into play. Most batteries will self discharge some small amount even in storage.
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It's not a minute amount in the off state, it is almost 90% of the on state. I used to slide a piece of very thin clear plastic between the battery and contacts and in some cases epoxied on an AA battery. Final solution was to buy the much better igaging EZ-Cal for $24 with a CR2032 battery
- Joined
- Dec 8, 2015
- Messages
- 127
I received my order today. Here is what you can expect.
I purchased one 12”, one 8” and two 6”. First impression is they are pretty darn nice for the money.
They came boxed up in the standard plastic cases.
The 12” and 8” are very smooth. The two 6” thumb wheels had a little bit of burr that you could feel as you rolled it. Cleaned that up and they both run smooth now.
I measured a ground bar, and all four calipers measured the same and repeated every time.
They will automatically turn on as soon as you move the slide. It’s a good feature, but that means the battery is really on in sleep mode – so shorter battery life. ( At least its that way on my Starretts.) They also auto shut off. The battery cover is held on by a screw from the back. I like that- others may not.
They also hold their zero when you turn them off and on – unlike the one set of HFs I had.
The installed batteries in two of the sets were dead. They come with extra batteries, and two of the spares looked a little leaky.
They seem every bit as good as any of the Chinese calipers. Of course YMMV.
Anyway, just sharing with you fine folks, what I thought was a good deal -if it fits your needs.
$20.88 worth of calipers. Delivered.
I purchased one 12”, one 8” and two 6”. First impression is they are pretty darn nice for the money.
They came boxed up in the standard plastic cases.
The 12” and 8” are very smooth. The two 6” thumb wheels had a little bit of burr that you could feel as you rolled it. Cleaned that up and they both run smooth now.
I measured a ground bar, and all four calipers measured the same and repeated every time.
They will automatically turn on as soon as you move the slide. It’s a good feature, but that means the battery is really on in sleep mode – so shorter battery life. ( At least its that way on my Starretts.) They also auto shut off. The battery cover is held on by a screw from the back. I like that- others may not.
They also hold their zero when you turn them off and on – unlike the one set of HFs I had.
The installed batteries in two of the sets were dead. They come with extra batteries, and two of the spares looked a little leaky.
They seem every bit as good as any of the Chinese calipers. Of course YMMV.
Anyway, just sharing with you fine folks, what I thought was a good deal -if it fits your needs.
$20.88 worth of calipers. Delivered.
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- Joined
- Feb 1, 2015
- Messages
- 9,992
AFAIK, any caliper that retains its zero setting draws current in the "off" state. Ironically, the one caliper that didn't retain its zero setting still drew essentially the same current as the ones that did. All drew about the same current as un the "on" state which leads me to believe that turning them off just turned off the display, leaving the rest of the circuit active.