Shadowing Practice: ATPL Instrumentation - Class 1: Temperature and Time - Learn English Speaking with Video
בחר מצב תרגול
כל מצב פותח חדר תרגול במסך מלא.
224 משפטים
אם המשפטים קצרים או ארוכים מדי, לחץ על ערוך כדי להתאים אותם.
1
If you're studying for your ATPLs and having a little bit of trouble with instrumentation, then this is the place to be.
2
Over the next few months, we're going to be breaking down all the topics within the instrumentation subject, analysing them and hopefully making them make sense for you in time for the exam.
3
Hi, I'm Grant and welcome to the first in a new series all about instrumentation.
4
There's lots of different things that we can measure on board an aircraft, and analyse to make certain decisions about where we need to go,
5
how high we need to fly and various other things.
6
The most fundamental and easy to understand though is temperature and time.
7
So we're going to start with them and slowly build up in complexity throughout the remainder of this course.
8
We need to sense the temperature of various components
9
so they don't overheat
10
and we also need to sense the temperature of the air around us to make sure we know
11
when to turn on any anti-ice systems and avoid any ice buildup.
12
We can measure temperature in Celsius, Fahrenheit or even Kelvin.
13
It doesn't really matter and the temperature probe will be calibrated to one of these
14
and then it can convert it if necessary or can do the conversions manually just like I've got at the top here.
15
So you've got Kelvin plus 273 equals Celsius.
16
Celsius times 9 over 5 plus 32 equals the Fahrenheit.
17
The simplest form of temperature sensor is to use a bi-metallic sensor.
18
This is where we use two different metals spiraled together and
19
when the temperature rises one metal will expand more than the other
20
which basically unwinds the spiral and rotates a needle on a display.
21
This is the sort of thing
22
that you might use to measure air temperature on a small aircraft
23
but you can't really measure the temperature of engine components
24
and display the information in a useful place because this biometallic strip can only be so long.
25
If you wanted to measure the temperature of the exhaust
26
and you wanted the display in the cockpit you need a biometallic strip
27
that went all the way to the back of the engine where the exhaust temperature was for example.
28
So simple, robust, very easy to understand but not
29
that useful for measuring some things but can be used in very simple applications.
30
A resistance temperature detector relies on a metal that will change in resistance when heated.
31
Four resistors are set up in this format essentially making a parallel circuit with a small battery outputting a consistent current.
32
The values of these three resistors are known and then this one down here is the variable resistance one.
33
As the resistance of this one changes it means
34
that the voltage passing through this side of a parallel circuit
35
measured at this point V2 will be different from the midpoint here at V1.
36
This resistor setup is fairly common in electronics
37
and it's called a wheat stone bridge if you're interested and want to look up more.
38
Because there is a difference in voltage between the two midpoints it means
39
that if we place a wire between point V1 and V2 we'll see that a current flows.
40
We can then use that current flow to turn a dial on a display
41
and the dial will turn based on how much resistance there is
42
because of how much voltage difference there is and that resistance changes depending on how much temperature there is.
43
So the temperature changes the resistance, changes the voltage, changes the voltage difference, turns the dial, gives us an effective display.
44
It's a good setup
45
and allows for the measurement of components from far away as all we need are longer wires to the display dial.
46
It does however need a constant DC power supply to make it work.
47
Thermocouples are used for very hot elements and work using a principle called Thermo-EMF, thermoelectromagnetic force.
48
This is when a metal creates a small voltage or electromagnetic force
49
when a temperature difference exists between two parts of the metal.
50
Basically say this is a metal rod
51
if it's hot over on the right hand side
52
and cold over on the left hand side a small voltage is produced in this metal.
53
Simple.
54
In a thermocouple we use two different metals.
55
We use metal one, let's just call it, and metal two in two sensing elements.
56
We also have a reference cold temperature.
57
This means we get a voltage difference produced when sensing a temperature which causes a current to flow.
58
Essentially we use that thermal EMF, we've got a hot and a cold, a hot and a cold we get a voltage generated in metal one
59
and a voltage generated in metal two because they're two different metals
60
that means that we're going to have a voltage difference
61
and then we do the same thing
62
that we did in the resistance temperature detector
63
and we hook up a dial and use the voltage difference and that current that's generated to turn the dial.
64
These are very effective because we can measure components from very far away just like we did with the
65
resistance temperature detector and it also doesn't need any power supply.
66
The problem is they aren't hugely accurate
67
so you wouldn't be using these for precision stuff
68
but depending on the metals used for the thermocouples they can
69
measure things at a very high temperature such as exhaust gas temperature in jet engines.
70
Air temperature is one of the most important things to measure
71
so that we can turn on any anti-icing systems when the temperature requires us to do so.
72
In light aircraft
73
that travel at low speed we tend to use a bi-metallic
74
type of temperature probe with the end of the gauge poking out into the airflow
75
and the dial giving us readings within the cockpit.
76
It's simple and effective but we run into a problem when we start to go faster.
77
Basically, as all the little particles in the air pass over the probe, they rub against it and create friction, causing the probe to heat up.
78
This distorts the results and doesn't give us a true reading
79
because we get this sort of kinetic heating effect whilst we're travelling through the air.
80
We therefore measure something that we call a total air temperature, or TAT.
81
and this is different from the actual air temperature which is the static air temperature
82
or sometimes referred to as the outside air temperature so you get sat, oat and tat.
83
That's a bit confusing and basically
84
when we add friction to the static air temperature we then are going to be measuring the total air temperature.
85
So how do we solve this problem?
86
Well we use clever design.
87
The most common type of probe and clever design that is used to get around this problem is called a Rosemount probe, which is I'm pretty sure a brand name,
88
but this style with a little variation is all over the place on different aircraft.
89
What happens in these probes is that air passes through this chamber past a small heater, which kind of seems a bit counter-intuitive,
90
but it's there to stop any ice formation on the front of this probe.
91
The venturi that follows the opening draws some of the air down into a sensing chamber
92
while the heavier particles that are in the air like water
93
or ice don't get drawn in and are free to pass by and they don't get sucked down into the sensing chamber.
94
In the chamber a resistance type temperature probe detects the heat of the air
95
before that air is dumped out the back of the probe.
96
The separate chamber eliminates most of the effects of the anti-icing heaters in the probe entry
97
and we can therefore get a reading for total air temperature
98
that is accurate and isn't affected by any need to de-ice
99
or anti-ice the probe
100
and it also gets rid of all the particles in the air for a more accurate reading as well.
101
It's important to note that this sort of probe will only work properly
102
when it's moving through the air or has air moving through it.
103
So when stationary, the air temperature readings will be way off and very, very high, especially if you've got the hot sun beating down on the probe, for example.
104
So we've got our measure for true air temperature, but we want to know the outside air temperature or the static air temperature.
105
What we do is we then use an equation
106
or more specifically there'll be a little bit of electronics that does this calculation for you.
107
The equation
108
that we use is the static air temperature equals the total
109
air temperature divided by 1 plus 3.2 times the recovery factor times the max squared.
110
The equation has a few things to note.
111
It must be used with Kelvin first of all,
112
which confuses things because sometimes the recovery factor gets given the symbol k.
113
And the recovery factor is essentially a measure of how efficient the probe is thermodynamically,
114
as this equation is a thermodynamic expression, for how much heat is added to the air by the speed we are going through,
115
hence the Mach number.
116
So let's just put some numbers in this and talk through an example.
117
So let's say we want to find out the outside air temperature, the static air temperature, and we have the following information.
118
We've got a total air temperature is minus 40,
119
that's what we measured, and we've got a recovery factor of 0.9
120
and we've got a Mach number of 0.75 and we want to find out what is the
121
static air temperature so the first thing we need to do is to convert it into Kelvin
122
so we're going going to add 273 and
123
that gives us an answer of 233 so 233 kelvin divided by 1 plus 0.2
124
times 0.9 times 0.75 squared we'll just leave that in there for now
125
and then I'll go away and do that on a calculator and see
126
that we've got 233 divided by 1.10125 dot dot
127
dot dot giving us a final answer in kelvin of 211.57 kelvin and if we wanted to convert that so let's
128
just do it back over here so we've got 211.57 kelvin want to convert that back into
129
um celsius so we take away 273
130
and we get an answer so that's uh yes celsius is here that's going to give us minus 61.
131
Yeah, 61.
132
So we can see that the friction of us travelling through the air, we're going from minus 61 actual outside air temperature
133
and we're adding about 20 degrees of friction to get us up to the total air temperature of minus 40.
134
So it has a big effect whilst we're travelling at relatively high Mach numbers.
135
In aviation, we measure things in UTC,
136
universal time coordinate, which is a standardised time zone throughout the world.
137
In the UK and parts of Europe, it is the same as the time in London, GMT, without daylight savings applied.
138
And in other parts, it might be a few hours different from local, or even vastly different in places like New Zealand,
139
where UTC is 12 hours different from local time.
140
Basically, things can get confusing if you're referencing times to aviation related things like weather reports
141
and arrival times which are all in UTC and then using your watch
142
or phone which might be in local time especially
143
when flying across different time zones with your phone maybe auto updating the time as you arrive in each place.
144
So to save us and help us with
145
that confusion we have a clock on the plane
146
which is set to UTC time for referencing all these things like weather reports
147
and arrival times etc and we call this the system clock.
148
We use this as our time source when we are flying.
149
These system clocks are the same as your wristwatch,
150
usually a quartz based timekeeping device on smaller aircraft with larger aircraft having more complicated clocks with various features
151
and they can use a GPS source to get an accurate time from the atomic clock
152
on board the satellites up in space.
153
They will also feature other things like a chrono which is a stopwatch used for timing short things.
154
For example we need the engines to run at idle for
155
at least three minutes before shutting them down after landing
156
so we'd want to start the chrono shortly after landing to ensure we have achieved that three minute cool down time.
157
We also have the elapsed time
158
which we can use for longer timing typically for the time
159
of pushback to the time of pulling back on stand again to get the block time of a flight, which is the flight time plus taxiing.
160
Or we could use to record just the flight time by selecting it on just before take off
161
and off just after landing.
162
Another important use for an onboard system clock is to get
163
an accurate measurement for how long the engine has been running and the the plane in general has been running.
164
Engines have parts that need to be checked after a certain number of hours.
165
So what we can do is we can manually record the startup
166
and shutdown times in a tech log using the system clock
167
and then we can get an accurate measurement of how long the engine has been running for
168
and how often we need to service parts and
169
when we need to service and check all of the components of the engine.
170
Most aircraft will not rely on manually noting down the times though
171
and they'll have a dedicated odometer that starts running when the engine starts and stops when the engine stops.
172
This gives an accurate figure of how many hours the engine has been running for
173
and it's kind of like the total mileage or total kilometreage odometer
174
that you get on a car
175
which gives an accurate figure of how long the engine has been on for
176
and maintenance can be planned according to the figures on this odometer.
177
In summary then you've got temperature sensing in a few different ways.
178
Most simple is a bimetallic strip.
179
You've got two different metals They untwine at different rates when heat is applied and the unspinning of one causes,
180
faster than the other, causes a dial to move and we can measure temperature.
181
Simple, but the biometallic strip limits how long it can be and how far away it can be from the source.
182
You get resistive type elements that use a wheatstone bridge setup.
183
the variable resistance reacts to heat and you'll get more or less heat and
184
heat and more or less resistance according to that heat.
185
You then get a voltage difference generated between each side of the Wheatstone bridge.
186
That voltage difference creates a current that current can be used to turn a dial.
187
They're good, they do rely on having a power source but it means that we can
188
take this display and just attach some wires
189
and send it to the cockpit away from the source of the temperature that we're measuring.
190
You also get thermocouples which have the benefit of not needing power.
191
They generate voltage when there's a temperature difference along their length.
192
So it's going to be hot over here
193
and it's going to be cold over here and that generates a voltage in this one metal, in this second metal,
194
because it's a slightly different metal it means there's a slightly different voltage generated
195
and we get two different voltages aka a voltage difference.
196
Voltage difference means current can flow and we can use
197
that flowing current to turn a dial which is proportional to the voltage difference and therefore proportional to the temperature
198
and we get an accurate measurement of temperature in the cockpit.
199
For air temperature sensing we generally on big aircraft use a rose mount probe.
200
It's good because it means it's not going to
201
ice up because there's heating elements here
202
and then we draw air down into this sensing chamber
203
and use a resistive type element to sense the temperature of the total air temperature
204
and we get rid of all the particles of water
205
and stuff in the air that might really affect and form this the result of the total air temperature.
206
We then use electronics,
207
we use an algorithm to calculate out what the static air temperature is compared to the total air temperature.
208
The formula is static air temperature
209
or outside air temperature equals the total air temperature divided by 1 plus 0.2 times the recovery factor times the Mach squared.
210
These temperatures are in Kelvin.
211
The recovery factor is a measurement of how efficient the resistive element
212
and this system in general is and sometimes can be given the symbol k
213
and then Mach is your Mach number
214
which is going to be a measurement of how fast this air is flowing through the probe
215
and how fast you're traveling through the air.
216
So a few things to remember with this equation, but it's a good way of figuring out the outside air temperature versus the total air temperature.
217
We also need to measure the time.
218
Time is very easy to understand.
219
It's UTC time, which is the universal worldwide time zone.
220
Everything in aviation is referenced to UTC.
221
So instead of using your watch where the local time might be vastly different to UTC,
222
you can use the system clock which is always set to UTC for all aviation related things.
223
And we can use accurate times from this to note down how long the engine's been running.
224
And then we know how often we have to serve those parts and when we need to service those parts.
הורד אפליקציה
כל מה שאתה צריך כדי לדבר בשטף
הגיית AIציון לכל משפט
תרגול IPAשלוט בכל צליל
אוצר מיליםבנה את מאגר המילים שלך
משחק אוצר מיליםלמד תוך כדי משחק
אותו ערוץ
FOR YOU
המלץ על סרטון
C194 משפטים
Transient Thermal Analysis in ANSYS AIM
Daily ConversationUniversity StudentsWorking Adults
C11
315 משפטים
PLC Programming Tutorial - Ladder Logic #2: Timers and Counters
Business EnglishUniversity StudentsWorking Adults
C13
5 משפטים
Full ATIS breakdown ✈️ #flighttraining #airlines #pilot
Business EnglishUniversity StudentsWorking Adults
B22
141 משפטים
QUALITY CONTROL Interview Questions & Answers! (Inspector, Manager + Assessor Interview Questions!
Business EnglishInterview EnglishUniversity Students
C12
544 משפטים
30+ C1 Level Vocabulary (Human Body) 🧠 || Learn Advanced English with Podcast
Business EnglishUniversity StudentsWorking Adults
C167 משפטים
STARTING AIR SYSTEM|HOW STARTING AIR IS ADMITTED IN CYLINDER UNIT| WHAT IS SLOW TURNING VALVE|
Business EnglishUniversity StudentsWorking Adults
B21
274 משפטים
WATCH this video before BECOMING A PILOT! Tips by CAPTAIN JOE
Business EnglishInterview EnglishUniversity Students
C22
112 משפטים
An Introduction to Basic Zabbix Concepts. Part One - Hosts, Items, and Triggers
Business EnglishUniversity StudentsWorking Adults
C13
85 משפטים
Material Properties 101
Business EnglishUniversity StudentsWorking Adults
C111
140 משפטים
Complete IELTS Band 5-6.5 - UNIT 6
IELTS PrepTOEIC PrepBusiness English
C11
19 משפטים
Types of Proximity Sensors! #automation #engineering #science #robotics #electronics
Daily ConversationUniversity StudentsWorking Adults
אוצר מילים והערות הגייה לשיעור הזה
שיעור הדיבור הזה ברמה C1 מבוסס על הסרטון “ATPL Instrumentation - Class 1: Temperature and Time”. המילים שחוזרות הכי הרבה: temperature, voltage, metal, probe, measure. בסרטון הזה יש 224 משפטים ו-2982 מילים לתרגול Shadowing. הדיבור נמשך 19:11. הדובר מדבר בקצב טבעי של כ-155 מילים בדקה, קרוב לשיחה יומיומית. 82% מהמילים נמצאות בין 3,000 המילים הנפוצות ביותר באנגלית; כדאי ללמוד את השאר לפני שמתחילים.
אוצר מילים מרכזי בסרטון הזה
15 המילים המתקדמות ביותר בסרטון, עם ההגייה והמשמעות שלהן:
| מילה | הגייה | משמעות |
|---|---|---|
| voltage שם עצם | /ˈvəʊltɪd͡ʒ/ | מֶתַח, ווֹלטָג׳ |
| probe שם עצם | /pɹoʊb/ | זונדה |
| kelvin שם עצם | /ˈkɛlvɪn/ | קלווין |
| measurement שם עצם | /ˈmɛʒ.ə.mənt/ | מְדִידָה |
| equation שם עצם | /ɪˈkweɪ.ʒən/ | משוואה \ מִשְׁוָאָה |
| cockpit שם עצם | /ˈkɑkˌpɪt/ | קוֹקְפִּיט |
| particle שם עצם | /ˈpɑɹtək(ə)l/ | חֶלְקִיק, גַרגִיר |
| minus | /ˈmaɪ.nəs/ | פחות, מינוס |
| resistor שם עצם | /ɹɪˈzɪstɚ/ | נגד |
| confuse פועל | /kənˈfjuːz/ | בלבל |
| detector שם עצם | /dɪˈtɛktə(ɹ)/ | גלאי |
| heater שם עצם | /ˈhitɚ/ | תנור חימום |
| metallic שם תואר | /məˈtæl.ɪk/ | מתכתי |
| calibrate פועל | /ˈkæl.ɪ.bɹeɪ̯t/ | כייל |
| unwind פועל | /ʌnˈwaɪnd/ | הִתְפַּרֵק |
Phrasal verbs שתשמעו
| מילה | משמעות |
|---|---|
| figure out פועל | הֵבִין, מצא תשובה |
| take off פועל | הֵסִיר, הוֹרִיד |
דקדוק בסרטון הזה
המבנים שהדובר משתמש בהם הכי הרבה, עם המילים המדויקות מהסרטון:
| מבנה | בסרטון |
|---|---|
| הווה מושלם ממושך (Present perfect continuous) have/has been + -ing — פעולה שהתחילה בעבר ועדיין נמשכת עכשיו | has been running · engine's been running |
| סביל (Passive voice) be + past participle — הדגש הוא על מה שקורה, לא על מי שעושה את הפעולה | will be calibrated · can be used · are set |
| משפטי זיקה (Relative clauses) who / which + clause — מידע נוסף על אדם או דבר | temperature which is · probe, which is · coordinate, which is |
| הווה מושלם (Present perfect) have/has + past participle — פעולה שקרתה בעבר ועדיין יש לה חשיבות או השפעה עכשיו | have achieved · has been |
הגייה ששווה לשים לב אליה
הדובר משתמש ב-46 קיצורים וצורות מקוצרות, כמו we're, we've, you're. אמרו אותם בצורה הקצרה, כפי שאתם שומעים אותם.
- הצלילים של “th”: thermodynamic /ˌθɝmoʊdaɪˈnæmɪk/, algorithm /ˈælɡəɹɪðm̩/, thermal /ˈθɜːməl/
- הצלילים של “sh” ו-“zh”: measurement /ˈmɛʒ.ə.mənt/, equation /ɪˈkweɪ.ʒən/, friction /ˈfɹɪkʃən/, stationary /ˈsteɪʃəˌnɛɹi/, calculation /ˌkælkjuˈleɪʃn̩/
- מילים ארוכות — שימו לב להטעמה: odometer /əʊˈdɒmətə/, manually /ˈmænj(u)əliː/, bimetallic /baɪmɪˈtælɪk/, thermodynamic /ˌθɝmoʊdaɪˈnæmɪk/, calculator /kæl.kjə.leɪ.tɚ/
צלילים שדוברי עברית מתקשים בהם:
- /w/ — שפתיים מעוגלות, לא /v/: equation /ɪˈkweɪ.ʒən/, untwine /ʌnˈtwʌɪn/, unwind /ʌnˈwaɪnd/, wristwatch /ˈɹɪstˌwɔt͡ʃ/, quartz /k(w)ɔɹts/
- /æ/ — פתוח יותר מה-“אֶ” העברית, לא כמו “a” ב-“cup”: static /ˈstæt.ɪk/, manually /ˈmænj(u)əliː/, vastly /ˈvæstli/, metallic /məˈtæl.ɪk/, bimetallic /baɪmɪˈtælɪk/
- /r/ — הלשון לא נוגעת בשום מקום, לא ה-“ר” הגרונית: probe /pɹoʊb/, friction /ˈfɹɪkʃən/, particle /ˈpɑɹtək(ə)l/, resistor /ɹɪˈzɪstɚ/, detector /dɪˈtɛktə(ɹ)/
איך לתרגל עם הסרטון הזה
- הקשיבו לכל הסרטון פעם אחת בלי לדבר, ורשמו את המילים שאתם לא מכירים.
- התחילו במהירות 0.75×, תרגלו Shadowing משפט אחר משפט, וחזרו למהירות רגילה כשזה מרגיש קל.
- הקליטו את עצמכם והשוו למקור, תוך תשומת לב למילים כמו voltage, probe, kelvin.
מהי טכניקת השאדואינג?
שאדואינג היא טכניקת למידת שפה מבוססת מדע שפותחה במקור להכשרת מתורגמנים מקצועיים ופופולרית על ידי הפוליגלוט ד"ר אלכסנדר ארגואלס. השיטה פשוטה אך עוצמתית: אתה מקשיב לאודיו באנגלית ילידית וחוזר עליו בקול רם מיד — כמו צל העוקב אחרי הדובר עם עיכוב של 1–2 שניות בלבד. בניגוד להאזנה פסיבית או תרגילי דקדוק, שאדואינג מכריח את המוח והשרירים בפה לעבד ולשחזר דפוסי דיבור אמיתיים בו זמנית. מחקרים מראים שזה משפר משמעותית את דיוק ההגייה, האינטונציה, הקצב, הדיבור המחובר, הבנת השמיעה ושטף הדיבור — מה שהופך אותו לאחת השיטות היעילות ביותר להכנה לIELTS Speaking ולתקשורת באנגלית בעולם האמיתי.