Instruments are tricky to make and maintain.
Unless there is a huge error in them it is very difficult to realize that something is wrong with them. For example, the weighing machine at your grocer has a slight error. It shows 1 kg of rice as 1.050 kg. Unless you are taking a huge quantity of rice, that error will never be caught by you or the grocer for that matter.
Most of the gadgets and appliances we use are commercially mass built. Approximation is inherently built in them. Accuracy is always given a second priority in them.
Let’s take a look at some of the gadgets you use every day that are not as reliable as you think they are.
1. Fuel gauges will show that your tank is empty even when there is a bit of fuel in the tank
Have you ever noticed that when you fill your tank full of petrol, the needle doesnt really leave the F mark for some time.
But as soon as the needle goes below the halfway mark, it starts dipping quicker than the first half. That is because analog gauges have a float mechanism to ascertain how much fuel is in the tank. The float is a ball and that is why when there is very little fuel left, the ball makes the needle touch E.
The digital gauges are not so smart either because most of them need regular calibration, otherwise they are going to show you an error that will leave you with an empty tank when there is still one bar left on the gauge.
2. Weighing scales are almost lethal in hospitals if they are wrong
“What’s the big deal?”, one might say. It is just a kilo off the actual weight.
Yes, you are right. For regular people it is not a big deal at all. But if you are a cancer patient, and you have to undergo radiation therapy, you need to check your weight properly because you get radiation proportional to your weight.
If the weighing scale is wrongly calibrated you might end up getting a bit too much of it which may turn out to be harmful to you.
This is when doctors in US and UK launched an investigation to check all the weighing gauges in hospitals and found out that almost one-third of all the scales were innaccurate.
3. Cellphones lie about how much charge they hold
Your phone never charges to a 100 percent. Because a fully charged battery degrades faster. That’s why the phones actually only charge until 95% and stop.
But the phones cannot show you that it has charged only 95%, because then you will never plug it out.
But it is for the phone’s safety, so chill out.
4. Almost 40% of the Blood pressure cuffs are faulty in readings
Have you ever noticed that if your blood pressure came a bit high, your doctor calls you for another reading the next day. But that does not matter because it may be because the instrument itself is faulty.
And if the instrument shows the blood pressure a few points below that it actually is, it is endangering a number of people who have high blood pressure because their readings will always be shown normal.
Always ask your doctor to show the calibration certificate of the cuff before getting your blood ressure measured.
5. Speedometers have error too
Although this is not exactly a problem in India, since the cops here do not have a digital speedometer that can be used to detect if you are speeding or not.
But this is not a big issue because the errors are not that large and unless you are driving a Bugatti with one of the faulty speedometers, you should be fine.
6. GPS routing algorithms lands people in all the wrong places
GPS systems are accurate when you are standing still. It starts screwing up when the navigation starts. Routing and rerouting is based on computer algorithms and not just the satellite feed and hence there have been cases where people have lost their way and even their lives because the map took them to a wrong place altogether.