Browse content similar to Episode 14. Check below for episodes and series from the same categories and more!
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Take a look around your home. | 0:00:03 | 0:00:05 | |
Can you be sure that every appliance is safe? | 0:00:07 | 0:00:10 | |
Is everything a company tells you about a product true? | 0:00:13 | 0:00:16 | |
And are you getting the best value for your money? | 0:00:17 | 0:00:21 | |
With the help of the country's top experts, we're going to see | 0:00:21 | 0:00:25 | |
what it takes to test the household products we use every day. | 0:00:25 | 0:00:29 | |
We'll discover how they're pushed to their limits... | 0:00:32 | 0:00:35 | |
..we'll put the makers' claims on trial... | 0:00:37 | 0:00:39 | |
..and show you how to make your money go further. | 0:00:41 | 0:00:44 | |
You'll find these products in any ordinary house, | 0:00:44 | 0:00:47 | |
but this is no an ordinary house, | 0:00:47 | 0:00:50 | |
and no ordinary street. | 0:00:50 | 0:00:53 | |
This is the Watchdog Test House. | 0:00:53 | 0:00:55 | |
Hello. We're deep inside one of Britain's leading science centres. | 0:01:01 | 0:01:06 | |
Here at the Building Research Establishment, some of the products | 0:01:06 | 0:01:09 | |
and materials that we use every day are put to the test | 0:01:09 | 0:01:14 | |
to make sure that they're safe, | 0:01:14 | 0:01:16 | |
environmentally friendly and that they don't fall apart. | 0:01:16 | 0:01:19 | |
Coming up on today's programme, | 0:01:20 | 0:01:22 | |
smoke alarms. A staggering one in four fail to go off in fires | 0:01:22 | 0:01:26 | |
attended by the fire brigade. | 0:01:26 | 0:01:28 | |
The smoke was coming out of the loft hatch quite severely, | 0:01:28 | 0:01:31 | |
and the smoke alarms didn't go off at all. | 0:01:31 | 0:01:34 | |
How do manufacturers try to ensure they're going to be fail-safe? | 0:01:34 | 0:01:38 | |
Fitness trackers - they claim to count calories and steps. | 0:01:39 | 0:01:42 | |
They're a fantastic motivation point. Track your calories | 0:01:42 | 0:01:45 | |
every day and try and improve on it day after day, run after run. | 0:01:45 | 0:01:48 | |
But how accurate are they? We put three products through their paces. | 0:01:48 | 0:01:53 | |
And exploding oven doors - no stranger to Watchdog... | 0:01:53 | 0:01:57 | |
..but aren't they supposed to be made of toughened glass? | 0:01:58 | 0:02:01 | |
Smoke alarms - the best way you to protect you | 0:02:07 | 0:02:10 | |
and your home against the threat of fire. | 0:02:10 | 0:02:13 | |
The good news? About 85% of households have them installed. | 0:02:13 | 0:02:17 | |
The bad news? They don't always go off. | 0:02:17 | 0:02:20 | |
The upstairs of the house was full of smoke. | 0:02:22 | 0:02:25 | |
I couldn't see where I was going. | 0:02:25 | 0:02:27 | |
Darren King was spending a Sunday afternoon at home with his two | 0:02:28 | 0:02:31 | |
children when his house caught fire. | 0:02:31 | 0:02:34 | |
My two sons were out the front playing, | 0:02:34 | 0:02:37 | |
and my eldest son came running in, just to say, "Daddy phone 999 - | 0:02:37 | 0:02:40 | |
"there's smoke coming out the roof." | 0:02:40 | 0:02:42 | |
When Darren went outside, he soon realised the fire was | 0:02:42 | 0:02:46 | |
actually inside the walls of the house. | 0:02:46 | 0:02:49 | |
The fire was actually started down in the bottom corner | 0:02:49 | 0:02:52 | |
of the threshold. | 0:02:52 | 0:02:53 | |
So I tried to put that out, and then when I came inside, | 0:02:53 | 0:02:58 | |
I put my hand on here and noticed there was a lot of heat | 0:02:58 | 0:03:00 | |
and I could hear crackling. | 0:03:00 | 0:03:01 | |
I realised at that point then that the fire was going all | 0:03:01 | 0:03:04 | |
the way up the cavity wall. | 0:03:04 | 0:03:06 | |
Before long, the flames had reached the roof. | 0:03:06 | 0:03:09 | |
That's how high the fire actually came up from the ground floor | 0:03:09 | 0:03:13 | |
back door, | 0:03:13 | 0:03:14 | |
and it's started burning through the wooden framework | 0:03:14 | 0:03:18 | |
of the actual house. | 0:03:18 | 0:03:19 | |
Darren called 999, and by the time the fire brigade had put | 0:03:19 | 0:03:23 | |
the flames out, the house was full of smoke, | 0:03:23 | 0:03:26 | |
but the smoke alarm was faulty and it never went off. | 0:03:26 | 0:03:29 | |
Luckily the fire was in the afternoon and not in the evening, | 0:03:29 | 0:03:33 | |
because if we'd been in bed, we wouldn't have noticed. | 0:03:33 | 0:03:36 | |
The smoke alarms wouldn't have gone off, | 0:03:36 | 0:03:38 | |
and we may not have got out of the house alive. | 0:03:38 | 0:03:40 | |
Fire brigade statistics show that in more than one in four | 0:03:40 | 0:03:44 | |
of the house fires they attend where a smoke alarm was present, | 0:03:44 | 0:03:48 | |
it failed to go off. | 0:03:48 | 0:03:49 | |
In Darren's case, the alarms were faulty, | 0:03:49 | 0:03:52 | |
but there can be plenty of other reasons too. | 0:03:52 | 0:03:55 | |
Smoke alarms have been going off, creating a false alarm, | 0:03:55 | 0:03:58 | |
and people have actually taken the batteries out | 0:03:58 | 0:04:00 | |
because of the nuisance factor, and forgot to put them back. | 0:04:00 | 0:04:03 | |
There are also issues with inadequate siting within the homes. | 0:04:03 | 0:04:07 | |
Smoke alarms must be sited where they can give adequate coverage | 0:04:07 | 0:04:10 | |
and protection, so they can be heard. | 0:04:10 | 0:04:12 | |
But of course that probably won't mean that it covers | 0:04:12 | 0:04:15 | |
every room within a house. | 0:04:15 | 0:04:16 | |
You also need to think about which type of alarm you buy. | 0:04:16 | 0:04:20 | |
Broadly, there are two types - ionisation and optical, | 0:04:20 | 0:04:24 | |
and fire and rescue services would recommend the fitting | 0:04:24 | 0:04:27 | |
of optical-type detectors in all but specific circumstances. | 0:04:27 | 0:04:31 | |
That's because optical detectors are safer in detecting | 0:04:31 | 0:04:35 | |
a broader range of fires. | 0:04:35 | 0:04:36 | |
Either way, you're better off with an alarm than without, | 0:04:36 | 0:04:40 | |
as you're four times as likely to die in a house fire | 0:04:40 | 0:04:43 | |
if you don't have a smoke alarm. | 0:04:43 | 0:04:45 | |
And to make sure they operate effectively, every model | 0:04:45 | 0:04:48 | |
on the market has to be thoroughly tested before going on sale. | 0:04:48 | 0:04:52 | |
Later in the programme, we'll be at the British Standards Institution, | 0:04:52 | 0:04:55 | |
to find out how. | 0:04:55 | 0:04:57 | |
Now, fitness trackers. | 0:05:01 | 0:05:02 | |
They monitor your activity throughout the day | 0:05:02 | 0:05:05 | |
and tell how many calories you burn. | 0:05:05 | 0:05:07 | |
They're marketed as the smartest way to stay active. | 0:05:07 | 0:05:11 | |
But just how accurate are they? | 0:05:11 | 0:05:12 | |
Well, Sophie, if you're anything like me and can't afford your own | 0:05:16 | 0:05:19 | |
personal trainer to keep on top of your exercise regime, you may | 0:05:19 | 0:05:22 | |
want turn to one of these nifty little gadgets for help. | 0:05:22 | 0:05:25 | |
Just ask this lot. | 0:05:25 | 0:05:27 | |
I just tell it I'm going running, | 0:05:29 | 0:05:30 | |
and it'll basically keep track of how far I've gone, | 0:05:30 | 0:05:34 | |
the speed that I'm going, | 0:05:34 | 0:05:36 | |
and then it gives me a breakdown of my run at the end of the run. | 0:05:36 | 0:05:39 | |
If you're the sort of person that likes to keep on top | 0:05:39 | 0:05:41 | |
of things, see your progress and so on, | 0:05:41 | 0:05:44 | |
I think these devices are excellent. | 0:05:44 | 0:05:47 | |
They're a fantastic motivation point. Track your calories | 0:05:47 | 0:05:50 | |
every day and try and improve on it day after day, run after run. | 0:05:50 | 0:05:53 | |
But just how reliable are these devices? | 0:05:53 | 0:05:57 | |
To find out, we've come to Brunel University, where, | 0:05:57 | 0:05:59 | |
with the help of Richard Godfrey - a lecturer in sports psychology, | 0:05:59 | 0:06:02 | |
Tom - a triathlete... | 0:06:02 | 0:06:05 | |
Hi, Tom. Nice to see you. I'm Richard. | 0:06:05 | 0:06:07 | |
..and Chris - the lab technician, | 0:06:07 | 0:06:09 | |
we're going to put two of their many claims to the test - | 0:06:09 | 0:06:12 | |
calories burnt and the number of steps taken. | 0:06:12 | 0:06:15 | |
Tom will be wearing three products chosen from the UK's | 0:06:15 | 0:06:18 | |
leading on-line retailers - | 0:06:18 | 0:06:21 | |
the cheapest we could find, the V-fit WSG pedometer, | 0:06:21 | 0:06:25 | |
costing just over £6, | 0:06:25 | 0:06:26 | |
a mid-range product, the Fitbit Zip, costing £49.99, | 0:06:26 | 0:06:31 | |
wand the top-of-the-range Nike+ FuelBand | 0:06:31 | 0:06:34 | |
which costs £129 - | 0:06:34 | 0:06:36 | |
all of which claim to monitor both calories and steps. | 0:06:36 | 0:06:39 | |
First up, calories. | 0:06:44 | 0:06:45 | |
Chris inputs Tom's vital statistics into all three devices | 0:06:45 | 0:06:49 | |
according to the manufacturers' instructions. | 0:06:49 | 0:06:52 | |
Then it's time for the work-out. | 0:06:52 | 0:06:54 | |
Three, two, one, go. | 0:06:55 | 0:06:58 | |
He's first of all going to do ten minutes of walking | 0:07:00 | 0:07:02 | |
at an easy pace, wearing the devices and having | 0:07:02 | 0:07:05 | |
oxygen consumption measured at the same time. | 0:07:05 | 0:07:08 | |
He'll then have a bit of a break before we get him to do | 0:07:08 | 0:07:10 | |
another ten minutes, this time at a higher intensity, just a jog, | 0:07:10 | 0:07:14 | |
slow jog, and then he'll have another break, | 0:07:14 | 0:07:17 | |
after which we'll do another ten minutes, this time at a faster jog. | 0:07:17 | 0:07:21 | |
As Tom exercises, his muscles use oxygen to burn fuel - or calories. | 0:07:22 | 0:07:28 | |
The more oxygen consumed, the more calories burned. | 0:07:28 | 0:07:32 | |
Therefore, by tracking Tom's oxygen consumption | 0:07:32 | 0:07:34 | |
throughout his work-out, Richard will have a scientifically accurate | 0:07:34 | 0:07:38 | |
measure of calorie expenditure. | 0:07:38 | 0:07:40 | |
He can then compare that to what our three devices say. | 0:07:40 | 0:07:43 | |
Five, four, three, two, one, stop. | 0:07:43 | 0:07:49 | |
With the work-out complete | 0:07:49 | 0:07:50 | |
and the calorie data captured from all three devices, | 0:07:50 | 0:07:53 | |
it's on to the second part of the test... | 0:07:53 | 0:07:55 | |
There we go. That's got to be better. | 0:07:55 | 0:07:57 | |
..steps taken. | 0:07:57 | 0:07:59 | |
For this, Tom moves onto another crucial bit of scientific kit - | 0:07:59 | 0:08:02 | |
the fire escape. | 0:08:02 | 0:08:04 | |
According to Government guidelines, it's recommended that you take | 0:08:05 | 0:08:08 | |
around 10,000 steps in a normal day. | 0:08:08 | 0:08:10 | |
That's roughly the equivalent of a five-mile walk. | 0:08:10 | 0:08:13 | |
So having an accurate idea of how many you've taken is important. | 0:08:14 | 0:08:18 | |
We know that it takes exactly 152 steps to go to the bottom | 0:08:20 | 0:08:24 | |
and back to the top. | 0:08:24 | 0:08:26 | |
What we don't know is how many steps our devices will think he's taken. | 0:08:26 | 0:08:30 | |
So just to make sure we're accurate, we do the test twice. | 0:08:32 | 0:08:35 | |
With the tests now complete, | 0:08:38 | 0:08:39 | |
it's time for Richard to crunch the numbers. | 0:08:39 | 0:08:42 | |
And we'll be bringing you the results later in the programme. | 0:08:42 | 0:08:45 | |
Next, exploding oven doors - | 0:08:49 | 0:08:52 | |
a sudden bang, with glass spraying out across the kitchen floor. | 0:08:52 | 0:08:56 | |
It's enough to give anyone a fright. | 0:08:56 | 0:08:58 | |
But why does this happen when oven doors are made from toughened glass? | 0:08:58 | 0:09:03 | |
A question for Lynn Faulds Wood. | 0:09:03 | 0:09:04 | |
ARCHIVE: 'Welcome to Watchdog. In tonight's programme... | 0:09:07 | 0:09:11 | |
'All these people have written to us.' | 0:09:11 | 0:09:14 | |
In the 1980s, oven doors made of glass were still a bit of a novelty. | 0:09:20 | 0:09:24 | |
Now, you might not have noticed, but over the past few years, | 0:09:24 | 0:09:27 | |
there's been a revolution in the way our cookers are designed. | 0:09:27 | 0:09:30 | |
But by 1988, hundreds of Watchdog viewers were complaining | 0:09:30 | 0:09:34 | |
that so-called toughened glass in their oven doors | 0:09:34 | 0:09:37 | |
had shattered without warning. | 0:09:37 | 0:09:39 | |
There was a tremendous crashing noise. I turned round to find | 0:09:42 | 0:09:46 | |
that the front glass of the cooker had exploded out, and he was | 0:09:46 | 0:09:50 | |
actually standing in all these small pieces of very hot glass. | 0:09:50 | 0:09:55 | |
Imagine that happening in your kitchen. | 0:09:55 | 0:09:58 | |
And we discovered it was down to the way the glass had been | 0:09:58 | 0:10:01 | |
fitted into the oven door. | 0:10:01 | 0:10:02 | |
We go to the bottom oven, the glass is held in with these clips and | 0:10:03 | 0:10:07 | |
there's no seal underneath, so it's pressing metal on the glass on both | 0:10:07 | 0:10:11 | |
sides. Finally, if I shut the door, I think you'll see the problem. | 0:10:11 | 0:10:15 | |
LOUD SMACK | 0:10:15 | 0:10:16 | |
That's not good enough - | 0:10:16 | 0:10:18 | |
it's stressing an already badly fixed door. | 0:10:18 | 0:10:21 | |
With criticism like that, no wonder manufacturers were persuaded | 0:10:21 | 0:10:25 | |
to spend millions improving door seals, hinges | 0:10:25 | 0:10:28 | |
and fittings to reduce the stress on the surface of the glass. | 0:10:28 | 0:10:32 | |
Philips even asked me to fly to their Italian factory | 0:10:32 | 0:10:35 | |
to see the changes they'd introduced. | 0:10:35 | 0:10:38 | |
The slot here that the glass fits into, before it was just two metal | 0:10:38 | 0:10:42 | |
pieces. Now it's a continuous metal piece all the way along. Much better. | 0:10:42 | 0:10:46 | |
But what is it about toughened glass that makes it prone to shattering | 0:10:47 | 0:10:51 | |
so spectacularly if fitted badly to the oven door? | 0:10:51 | 0:10:55 | |
Toughened glass is used in all sorts of modern inventions, | 0:10:56 | 0:11:00 | |
from patio doors to windows in your car, | 0:11:00 | 0:11:03 | |
but its origins date all the way back to the 17th century. | 0:11:03 | 0:11:07 | |
Prince Rupert of Bavaria came across the phenomenon by accident. | 0:11:09 | 0:11:14 | |
He found dropping hot molten glass into cold water formed | 0:11:14 | 0:11:18 | |
tadpole-shaped droplets. | 0:11:18 | 0:11:20 | |
These "Rupert drops", as they became known, | 0:11:20 | 0:11:22 | |
have remarkable properties. | 0:11:22 | 0:11:24 | |
CLINK The fat end is surprisingly strong. | 0:11:24 | 0:11:28 | |
As you can see, it has survived the impact. | 0:11:28 | 0:11:30 | |
The thin end, however, shatters | 0:11:30 | 0:11:32 | |
at the slightest touch. | 0:11:32 | 0:11:34 | |
The drop has disappeared. It has completely shattered. | 0:11:36 | 0:11:40 | |
Why? When the hot glass is plunged into the cold water, | 0:11:40 | 0:11:44 | |
the outside hardens really quickly. | 0:11:44 | 0:11:46 | |
The glass on the inside, though, cools much more slowly, and like | 0:11:46 | 0:11:50 | |
a coiled spring, it pushes against the already hardened outside layer. | 0:11:50 | 0:11:55 | |
It's this tension between the inner glass pushing out against | 0:11:55 | 0:11:58 | |
the already hardened outside surface that makes the droplet so strong. | 0:11:58 | 0:12:03 | |
But if you damage that outside surface, | 0:12:03 | 0:12:06 | |
the inner tension is released, | 0:12:06 | 0:12:08 | |
and the droplet explodes into tiny, harmless fragments. | 0:12:08 | 0:12:12 | |
And that's exactly the principles on which toughened glass is based. | 0:12:12 | 0:12:17 | |
The glass is taken up to about 700 degrees | 0:12:17 | 0:12:20 | |
and cooled very quickly with air jets. | 0:12:20 | 0:12:22 | |
This has the same effect, where you get compressive layers | 0:12:22 | 0:12:25 | |
under the surface and tension in the centre. | 0:12:25 | 0:12:28 | |
At any point, if any scratch goes into that compressive layer, | 0:12:28 | 0:12:32 | |
the glass will break. | 0:12:32 | 0:12:34 | |
But it was its ability to be both strong and also break into harmless | 0:12:37 | 0:12:41 | |
fragments that caught the attention of the car industry. | 0:12:41 | 0:12:45 | |
This is what can happen with a windscreen | 0:12:48 | 0:12:50 | |
made of toughened safety glass. | 0:12:50 | 0:12:53 | |
As more cars came onto the roads in the '20s and '30s, | 0:12:54 | 0:12:57 | |
the numbers of accidents increased, | 0:12:57 | 0:13:00 | |
and with many injuries being caused by the windows breaking | 0:13:00 | 0:13:03 | |
into razor sharp pieces, toughened glass seemed the perfect solution. | 0:13:03 | 0:13:07 | |
The first British Standard for this glass in cars | 0:13:08 | 0:13:11 | |
was introduced in 1939. | 0:13:11 | 0:13:13 | |
Demand increased in the 1960s, as regulations were introduced actually requiring it | 0:13:13 | 0:13:19 | |
to be used in cars and in certain windows in buildings. | 0:13:19 | 0:13:24 | |
Today, wherever it's used, to meet current European standards, | 0:13:29 | 0:13:33 | |
toughened glass needs to be strong enough | 0:13:33 | 0:13:35 | |
to withstand the force of anything that might be thrown at it, | 0:13:35 | 0:13:39 | |
and when I say anything... | 0:13:39 | 0:13:41 | |
One, two... | 0:13:41 | 0:13:42 | |
The weight of it, being 50kg, | 0:13:49 | 0:13:52 | |
is very similar to a child running into a window, so it will | 0:13:52 | 0:13:55 | |
demonstrate that that window or that patio door can survive that impact. | 0:13:55 | 0:13:59 | |
But again, despite its vast strength, | 0:14:00 | 0:14:03 | |
compromise that outer layer with a couple of scratches | 0:14:03 | 0:14:07 | |
and it becomes extremely vulnerable | 0:14:07 | 0:14:11 | |
and collapses into those harmless little cubes or dice. | 0:14:11 | 0:14:15 | |
So looking back to those poorly designed oven doors, | 0:14:15 | 0:14:19 | |
those exposed metal rims and clips that were | 0:14:19 | 0:14:22 | |
pressing on the toughened glass were in fact compromising | 0:14:22 | 0:14:26 | |
the surface in the same way as that scratch. | 0:14:26 | 0:14:30 | |
And the result? | 0:14:30 | 0:14:31 | |
Although the design of oven doors has much improved, | 0:14:33 | 0:14:36 | |
toughened glass will always have the potential to become | 0:14:36 | 0:14:39 | |
'compromised. But whether it's been scratched or chipped during | 0:14:39 | 0:14:43 | |
'manufacture, or even as a result of aggressive cleaning...' | 0:14:43 | 0:14:46 | |
At least you know with toughened glass | 0:14:46 | 0:14:49 | |
that if it does shatter, it won't go into long, sharp shards | 0:14:49 | 0:14:53 | |
but rather into something safer like this. | 0:14:53 | 0:14:57 | |
If you're thinking about buying a car, there's certainly | 0:15:02 | 0:15:05 | |
an awful lot to choose from, | 0:15:05 | 0:15:07 | |
so where do you start, and is it ever good value to buy a new one? | 0:15:07 | 0:15:12 | |
Well, Emma Butcher from What Car? is with us now. Is it? | 0:15:12 | 0:15:15 | |
Well, surprisingly, sometimes it can, yes. | 0:15:15 | 0:15:18 | |
Most people would think that buying new didn't represent good value | 0:15:18 | 0:15:21 | |
at all over buying used, because, of course, | 0:15:21 | 0:15:23 | |
when you drive away from the forecourts you get that massive | 0:15:23 | 0:15:26 | |
hit of depreciation that can be up to 20% of the cost of the car. | 0:15:26 | 0:15:30 | |
However, there are some amazing discounts out there at the moment, | 0:15:30 | 0:15:34 | |
because manufacturers and car dealers, | 0:15:34 | 0:15:36 | |
they really want you to buy a new car, | 0:15:36 | 0:15:38 | |
and they're incentivising that, so that can be anything from a finance | 0:15:38 | 0:15:42 | |
package with ultra-low interest rates, sometimes even 0% interest, | 0:15:42 | 0:15:47 | |
to throwing in some free insurance or free servicing. | 0:15:47 | 0:15:51 | |
So, potentially, you could be getting a better deal on a new car. | 0:15:51 | 0:15:54 | |
What about the claims that car manufacturers make? | 0:15:54 | 0:15:57 | |
Is it easy to compare them? | 0:15:57 | 0:15:59 | |
Well, it's a bit of a lottery. You would think that you could | 0:15:59 | 0:16:01 | |
benchmark them, but our research has found no, | 0:16:01 | 0:16:04 | |
so those MPG figures that you see | 0:16:04 | 0:16:05 | |
advertised basically come from Government-mandated laboratory tests | 0:16:05 | 0:16:09 | |
which every car-maker must put its car through before they go on sale, | 0:16:09 | 0:16:14 | |
but because they're conducted in a lab, that doesn't really reflect | 0:16:14 | 0:16:18 | |
what happens when you're out in real traffic conditions. | 0:16:18 | 0:16:20 | |
At What Car? we've tested about 400 different engines now, | 0:16:20 | 0:16:24 | |
and we take cars out on the road, in real traffic, | 0:16:24 | 0:16:27 | |
and work out their true MPG based on their tailpipe emissions, | 0:16:27 | 0:16:31 | |
and we found that on average there can be | 0:16:31 | 0:16:33 | |
a 17% shortfall from what is actually claimed that a car can do | 0:16:33 | 0:16:37 | |
to what it actually achieves in real life. | 0:16:37 | 0:16:39 | |
So when you're buying a new car, what should you look out for? | 0:16:39 | 0:16:42 | |
First of all, make sure that you take the car out for a test drive. | 0:16:42 | 0:16:45 | |
Don't ever buy without doing that. | 0:16:45 | 0:16:46 | |
It's a really good idea to take someone with you who can | 0:16:46 | 0:16:49 | |
distract the sales person so you can concentrate on the drive, | 0:16:49 | 0:16:52 | |
and, similarly, you might want to leave the kids at home | 0:16:52 | 0:16:54 | |
if you think they'll distract you as well, although do take | 0:16:54 | 0:16:57 | |
along the buggies and the car seats to see what kind of a fit they make. | 0:16:57 | 0:17:01 | |
-Emma, good advice. Thank you very much. -Thank you. | 0:17:01 | 0:17:03 | |
Earlier, we put three fitness trackers through their paces. | 0:17:07 | 0:17:11 | |
From the cheapest to the most expensive, they all claimed | 0:17:11 | 0:17:15 | |
to count the number of calories burnt and the number of steps taken. | 0:17:15 | 0:17:19 | |
So how did they perform? Let's find out. | 0:17:19 | 0:17:21 | |
First up, counting steps. | 0:17:25 | 0:17:27 | |
We asked triathlete Tom to climb up and down | 0:17:27 | 0:17:30 | |
this 152-step fire escape twice. | 0:17:30 | 0:17:32 | |
The actual number of steps is 304, | 0:17:34 | 0:17:37 | |
but how many did our devices record? | 0:17:37 | 0:17:39 | |
Starting with our most expensive product, the Nike+ FuelBand, | 0:17:41 | 0:17:46 | |
costing £129. | 0:17:46 | 0:17:47 | |
It didn't do quite so well, counting 281 steps - | 0:17:47 | 0:17:51 | |
23 under the actual number. | 0:17:51 | 0:17:52 | |
Quite surprising for a device as expensive as it is. | 0:17:52 | 0:17:55 | |
The Fitbit Zip, our mid-range product, costing £49.99, | 0:17:55 | 0:18:00 | |
did much better - it was only out by two steps. | 0:18:00 | 0:18:03 | |
As for our cheapest product, at just over £6, the V-fit WSG pedometer... | 0:18:05 | 0:18:10 | |
In terms of counting steps, the pedometer did really well indeed. | 0:18:10 | 0:18:13 | |
304 steps were taken and it counted 305, | 0:18:13 | 0:18:17 | |
so that's really good for a relatively cheap device. | 0:18:17 | 0:18:19 | |
Yes, our cheapest device actually performed the best. | 0:18:19 | 0:18:23 | |
It miscounted by just one step over the course of the two tests. | 0:18:23 | 0:18:27 | |
The pedometer's quite a simple device | 0:18:27 | 0:18:29 | |
and it's therefore best at measuring simple linear movement, | 0:18:29 | 0:18:33 | |
so simply counting steps is what it does very well. | 0:18:33 | 0:18:36 | |
So if it's just counting steps you're looking for, | 0:18:36 | 0:18:39 | |
a cheaper product may well be perfectly adequate. | 0:18:39 | 0:18:42 | |
But how good were the devices at measuring calorie-burn? | 0:18:44 | 0:18:47 | |
Now, remember, during his work-out Richard asked Tom to walk, | 0:18:47 | 0:18:50 | |
jog and run. He monitored Tom's oxygen consumption | 0:18:50 | 0:18:53 | |
throughout as a measure of fuel consumption | 0:18:53 | 0:18:56 | |
and therefore a more accurate record of calorie-burn. | 0:18:56 | 0:18:58 | |
He then compared that to what the three devices said. | 0:18:59 | 0:19:02 | |
Three, two, one, stop. | 0:19:02 | 0:19:04 | |
In terms of estimated calorie expenditure, | 0:19:06 | 0:19:09 | |
the Nike+ FuelBand, the most expensive device, did the best. | 0:19:09 | 0:19:12 | |
With our laboratory-based kit, we measured 248 calories. | 0:19:12 | 0:19:16 | |
The Nike FuelBand measured 310, so 62 more, which is actually very good | 0:19:16 | 0:19:20 | |
for a device of that type. | 0:19:20 | 0:19:22 | |
Our cheapest product, the V-fit WSG pedometer, struggled. | 0:19:22 | 0:19:27 | |
Whilst our laboratory based kit measured 248 calories, the V-fit | 0:19:27 | 0:19:31 | |
only measured 125 - a difference of 123 calories. | 0:19:31 | 0:19:35 | |
But it was the mid-range product, the Fitbit Zip, that performed the worst. | 0:19:37 | 0:19:41 | |
It measured 432 - an overestimation of 184 calories. | 0:19:43 | 0:19:48 | |
None of the devices was completely accurate. | 0:19:52 | 0:19:54 | |
However, the Fitbit Zip was the worst one, | 0:19:54 | 0:19:56 | |
overestimating by almost half a chocolate bar. | 0:19:56 | 0:19:58 | |
So if you used that device, you'd actually think you'd expended | 0:19:58 | 0:20:01 | |
a lot more energy than you really had. | 0:20:01 | 0:20:03 | |
But according to Richard, it might not be all bad news. | 0:20:05 | 0:20:09 | |
Well, measuring calories is very useful, but being consistent | 0:20:09 | 0:20:12 | |
is also important, and the device has to measure consistently. | 0:20:12 | 0:20:15 | |
So you have to know that it's you that's improved in any change | 0:20:15 | 0:20:18 | |
that you see, and not some quirk of the device. | 0:20:18 | 0:20:20 | |
So, time for one final test - consistency. | 0:20:22 | 0:20:25 | |
We had Tom repeat the work-out to see if the devices gave | 0:20:25 | 0:20:28 | |
the same measurements for calorie-burn the second time around. | 0:20:28 | 0:20:31 | |
First up, our cheapest product, the V-fit WSG pedometer. | 0:20:32 | 0:20:37 | |
Although again it wasn't very accurate, | 0:20:37 | 0:20:39 | |
it was at least consistent, as it gave an almost identical | 0:20:39 | 0:20:42 | |
incorrect calorie reading on our second test. | 0:20:42 | 0:20:44 | |
Next, our mid-range product, the Fitbit. | 0:20:45 | 0:20:48 | |
Not only was it the least accurate | 0:20:48 | 0:20:50 | |
when counting calories, it was also the least consistent. | 0:20:50 | 0:20:53 | |
For both those work-outs, you'd expect to see | 0:20:53 | 0:20:55 | |
the same results - you want to see reproducibility. | 0:20:55 | 0:20:58 | |
That didn't happen. There was a big, big difference, | 0:20:58 | 0:21:00 | |
which means it's not a particularly reliable device | 0:21:00 | 0:21:02 | |
and it doesn't assess performance particularly well. | 0:21:02 | 0:21:05 | |
As for the Nike+ FuelBand, our most expensive product, not only was it | 0:21:05 | 0:21:09 | |
the most accurate, it was also the most consistent - | 0:21:09 | 0:21:13 | |
at least in our test. | 0:21:13 | 0:21:14 | |
The Nike FuelBand did much better. It showed greater consistency, | 0:21:14 | 0:21:17 | |
and that's exactly what we want in devices of this type. | 0:21:17 | 0:21:19 | |
That's the name of the game. | 0:21:19 | 0:21:21 | |
Fitbit told us they are surprised | 0:21:21 | 0:21:23 | |
and disappointed with the results of our test, which they say | 0:21:23 | 0:21:26 | |
do not represent the normal experience of their customers. | 0:21:26 | 0:21:29 | |
They say the tracker has undergone thousands of scientific tests, | 0:21:29 | 0:21:33 | |
should be at least 95% accurate, | 0:21:33 | 0:21:36 | |
and they do everything to ensure customer experience is positive. | 0:21:36 | 0:21:40 | |
But whatever the device you choose to wear, | 0:21:40 | 0:21:42 | |
according to Richard, there is at least one benefit they all share. | 0:21:42 | 0:21:45 | |
With these devices, they're incredibly motivating. | 0:21:45 | 0:21:47 | |
You can upload information, you can share it with family and friends, | 0:21:47 | 0:21:51 | |
you can introduce elements of competition - | 0:21:51 | 0:21:52 | |
all of this means these devices are motivating. | 0:21:52 | 0:21:56 | |
So maybe these little devices CAN be your own personal trainer - | 0:21:56 | 0:21:59 | |
just as long as you're not always expecting a precision calorie-count | 0:21:59 | 0:22:02 | |
along the way. | 0:22:02 | 0:22:03 | |
Back to smoke alarms now. | 0:22:08 | 0:22:10 | |
You're four times more likely to die in a house fire | 0:22:10 | 0:22:14 | |
if there is no working smoke alarm. | 0:22:14 | 0:22:16 | |
So what do manufacturers do to try to ensure they're fail-safe? | 0:22:16 | 0:22:20 | |
Test them, of course. | 0:22:20 | 0:22:22 | |
The British Standards Institution in Hemel Hempstead. | 0:22:22 | 0:22:26 | |
Here they don't just test products - they help write the rule book, | 0:22:26 | 0:22:30 | |
known as the Standards. | 0:22:30 | 0:22:31 | |
BSI was established in 1901. | 0:22:31 | 0:22:34 | |
At the time, it was the world's first national standards body, | 0:22:34 | 0:22:37 | |
and remains today the UK national standards body. | 0:22:37 | 0:22:41 | |
For a smoke alarm to meet current safety standards, | 0:22:41 | 0:22:43 | |
it has to pass more than 40 tests. | 0:22:43 | 0:22:46 | |
It's critical that these products do actually | 0:22:47 | 0:22:50 | |
perform the function that they're designed for. | 0:22:50 | 0:22:52 | |
The last thing you want is to have a smoke alarm fitted | 0:22:52 | 0:22:55 | |
in your house which doesn't go off in the event of a fire. | 0:22:55 | 0:22:58 | |
Today we're going to be demonstrating some of those tests, | 0:22:58 | 0:23:01 | |
using a mid-range smoke alarm currently on the market | 0:23:01 | 0:23:04 | |
for about £20. | 0:23:04 | 0:23:06 | |
We're starting with the most important piece of machinery - | 0:23:06 | 0:23:09 | |
the smoke tunnel. | 0:23:09 | 0:23:10 | |
We used to actually create real smoke for the tunnel, | 0:23:11 | 0:23:15 | |
using this heated bar, here. | 0:23:15 | 0:23:17 | |
Now we use atomised liquid paraffin. | 0:23:17 | 0:23:19 | |
It's a much more controllable way of producing simulated smoke. | 0:23:19 | 0:23:24 | |
So, in goes the alarm, | 0:23:24 | 0:23:26 | |
then the smoke is blown gently around the tunnel, | 0:23:26 | 0:23:30 | |
not that you'll be able to see it. | 0:23:30 | 0:23:32 | |
It's very, very small quantities. | 0:23:32 | 0:23:33 | |
So we're talking literally parts of a million, here. | 0:23:33 | 0:23:36 | |
So when the smoke alarms are actually triggered, you wouldn't | 0:23:36 | 0:23:39 | |
be able to see with the human eye the smoke in the atmosphere. | 0:23:39 | 0:23:43 | |
The thickness of the smoke is gradually increased in order | 0:23:43 | 0:23:46 | |
to measure exactly how much is needed to set the alarm off. | 0:23:46 | 0:23:50 | |
ALARM BLEEPS | 0:23:50 | 0:23:53 | |
What we're looking for here is to make sure it doesn't go off | 0:23:53 | 0:23:56 | |
at too sensitive a level, otherwise, obviously, it would | 0:23:56 | 0:23:58 | |
be going off at all hours of the night, and giving false readings. | 0:23:58 | 0:24:02 | |
Effectively, it has to trigger at a higher point than 0.2dB per metres, | 0:24:02 | 0:24:07 | |
and it triggered at 0.87, which is technically a pass. | 0:24:07 | 0:24:11 | |
What we have to do now is take five more measurements, | 0:24:11 | 0:24:14 | |
and then we'll assess the results to ensure | 0:24:14 | 0:24:16 | |
the ratio between the highest and lowest trigger point isn't too wide. | 0:24:16 | 0:24:20 | |
Effectively, what we're looking for here is to ensure that the product, | 0:24:20 | 0:24:24 | |
once it's operated once, | 0:24:24 | 0:24:25 | |
will operate again in the future at the same levels. | 0:24:25 | 0:24:29 | |
Checking the consistency of the alarm in this way | 0:24:29 | 0:24:32 | |
is called repeatability. | 0:24:32 | 0:24:34 | |
Next, they need to find out whether it has any weak spots. | 0:24:34 | 0:24:37 | |
This box is the ionisation chamber, | 0:24:37 | 0:24:40 | |
so this is the actual detector of the smoke. | 0:24:40 | 0:24:43 | |
We want to ensure that regardless of where the smoke's coming in, | 0:24:43 | 0:24:46 | |
it will reach that chamber and the alarm will trigger. | 0:24:46 | 0:24:49 | |
And you can see that if the smoke enters at this point, it has | 0:24:49 | 0:24:52 | |
a lot of electronic components that it has to negotiate before it | 0:24:52 | 0:24:55 | |
will actually reach that chamber and detect smoke. | 0:24:55 | 0:24:58 | |
We'll put the product back into the smoke tunnel, | 0:24:58 | 0:25:01 | |
and we'll turn it round at 45 degree angles. | 0:25:01 | 0:25:04 | |
Once we've identified the worst point of access for the smoke, | 0:25:04 | 0:25:08 | |
we'll carry out the rest of the tests in that particular orientation | 0:25:08 | 0:25:12 | |
to ensure it's the worst-case scenario. | 0:25:12 | 0:25:14 | |
Once you know that an individual alarm works, | 0:25:14 | 0:25:17 | |
and in all positions, you need to be sure each one manufactured | 0:25:17 | 0:25:21 | |
is roughly the same. The way to do that? | 0:25:21 | 0:25:23 | |
Test another 20. And if they're sufficiently consistent, | 0:25:23 | 0:25:27 | |
it's time for extreme conditions. | 0:25:27 | 0:25:30 | |
What we're doing now is adjusting the temperature of the smoke tunnel. | 0:25:30 | 0:25:34 | |
We're going to do two tests in here. | 0:25:34 | 0:25:36 | |
We'll do a cold operational test at nought degrees C, | 0:25:36 | 0:25:38 | |
and a dry heat test at 55 degrees C. | 0:25:38 | 0:25:43 | |
If you have a product which is installed in a house and it's | 0:25:43 | 0:25:45 | |
a particularly cold night, we want to make sure that it will activate | 0:25:45 | 0:25:49 | |
when it's supposed to as well as it would do on a very hot, sunny day. | 0:25:49 | 0:25:52 | |
So once you know the alarm can sniff out smoke in all manner | 0:25:52 | 0:25:55 | |
of conditions, attention turns to sound. | 0:25:55 | 0:25:58 | |
And for that you'll need some peace and quiet. | 0:25:58 | 0:26:02 | |
This is one of our special test chambers. | 0:26:04 | 0:26:06 | |
It's called an anechoic chamber. | 0:26:06 | 0:26:08 | |
We're using it to measure the volume of the smoke alarm in this case, | 0:26:08 | 0:26:12 | |
and what we don't want to do is to have the sound | 0:26:12 | 0:26:14 | |
bouncing off the walls back to our measuring equipment. | 0:26:14 | 0:26:17 | |
We only want to hear it once, as it comes out of the actual alarm itself. | 0:26:17 | 0:26:21 | |
You can see the construction of the room here. | 0:26:21 | 0:26:23 | |
It's covered with these special foam cones, | 0:26:23 | 0:26:26 | |
which are designed to trap and absorb the sound. | 0:26:26 | 0:26:29 | |
It's a very strange feeling with the door shut, | 0:26:29 | 0:26:31 | |
because you literally can't hear anything. | 0:26:31 | 0:26:33 | |
You can hear the pulse of your blood in your ears, | 0:26:33 | 0:26:35 | |
and when you talk it sounds as though you're actually talking in your head, | 0:26:35 | 0:26:39 | |
because there's literally no echo at all. | 0:26:39 | 0:26:41 | |
HEARTBEAT | 0:26:41 | 0:26:43 | |
The perfect environment for accurately measuring noise. | 0:26:43 | 0:26:46 | |
ALARM BLEEPS | 0:26:48 | 0:26:51 | |
What we're looking for is a sound level in excess of 85 decibels | 0:26:51 | 0:26:55 | |
when measured at three metres from the alarm point. | 0:26:55 | 0:26:58 | |
What we can't do is exceed 110 decibels. | 0:26:58 | 0:27:00 | |
Basically, those parameters are set so that the alarm is loud enough | 0:27:00 | 0:27:04 | |
to be heard when it needs to be, but not so loud | 0:27:04 | 0:27:06 | |
that it becomes debilitating. | 0:27:06 | 0:27:08 | |
So, your smoke alarm detects smoke and makes the right amount of noise. | 0:27:08 | 0:27:13 | |
One last thing - is it robust? | 0:27:13 | 0:27:15 | |
Yes, that's our alarm being hit with a hammer. | 0:27:15 | 0:27:19 | |
What we're trying to do here is to replicate the kind of impact that | 0:27:19 | 0:27:22 | |
it might realistically experience during the course of its lifetime - | 0:27:22 | 0:27:25 | |
from the point of manufacture, transportation, installation. | 0:27:25 | 0:27:29 | |
You might drop it on the floor... All these things we take into | 0:27:29 | 0:27:32 | |
consideration, and we're trying to replicate the worst kind of impact | 0:27:32 | 0:27:35 | |
that it's likely to experience. | 0:27:35 | 0:27:37 | |
A single blow measuring 1.6 joules, to be precise. | 0:27:37 | 0:27:42 | |
And if it survives, you can always try shaking it to bits. | 0:27:42 | 0:27:46 | |
What we're doing is subjecting it to different | 0:27:46 | 0:27:49 | |
cycles of vibration in three different axes. | 0:27:49 | 0:27:51 | |
So forward and backwards, side to side, and up and down. | 0:27:51 | 0:27:54 | |
At the end of the vibration test, we'll do a visual inspection. | 0:27:54 | 0:27:57 | |
We need to make sure that the cover is still attached, | 0:27:57 | 0:27:59 | |
that the electronic components are still firmly fixed to the board. | 0:27:59 | 0:28:02 | |
And then what we'll do is put it back together, | 0:28:02 | 0:28:05 | |
put it into the smoke tunnel, and subject it to the same smoke tests | 0:28:05 | 0:28:08 | |
that we did previously, to make sure that it still activates | 0:28:08 | 0:28:10 | |
in accordance with the manufacturer's specification. | 0:28:10 | 0:28:13 | |
If you want more information on the safety of products in your home, | 0:28:17 | 0:28:20 | |
you can go to our website: | 0:28:20 | 0:28:25 | |
That's all for today. Thanks for watching. | 0:28:28 | 0:28:30 |