Pressure sensor

Name:

Date:

Class:

Quick Questions

Shade in the A or B circle for each question.

1. Which data does a pressure sensor capture?

A The force applied over an area by a gas, liquid or solid

B The amount of light falling on it

2. A car's tyre pressure monitor warns the driver about a flat tyre. Which sensor does it use?

A Humidity sensor

B Pressure sensor

3. Which use of a pressure sensor is correct for weather forecasting?

A Measuring air pressure to help predict changes in the weather

B Measuring the sound of thunder to work out the temperature

4. A pressure pad is placed on the floor and detects when someone steps on it. True or false: it uses a pressure sensor.

A False

B True

5. A factory must keep the pressure inside a chemical tank within safe limits. Which sensor is most suitable?

A Pressure sensor

B Infra-red sensor

Match the Pairs

Draw a line connecting each item on the left to its match on the right.

Left column		Right column
1pressure sensor		AA pressure sensor inside a tyre that warns the driver when the air pressure is too low
2tyre pressure monitor		BPressure sensors can measure the force applied by a gas, a liquid or a solid, for example in industrial processes and pressure pads.
3A weather station uses a pressure sensor to measure air pressure for weather forecasting		CAn input device that measures the force applied over an area by a gas, liquid or solid
4A pressure pad sends a reading to the microprocessor when someone steps on it		DIF padPressure > 0 THEN SoundAlarm()
5A pressure sensor measures the temperature of the air in a tyre		EA pressure sensor measures pressure (force over an area), not temperature. A temperature sensor measures how hot or cold something is.
6Pressure sensors can only measure the pressure of gases		FIF airPressure < 1000 THEN OUTPUT "Storm likely"

Definitions

pressure sensor

Fill in the Blanks

Complete each line of code by filling in the missing parts.

IF tyrePressure _ 30 THEN OUTPUT "Low tyre pressure" ENDIF

__ padPressure > 0 THEN OUTPUT "Person detected" ENDIF

// Weather station air pressure reading pressure ← READ(______________) OUTPUT pressure

pressure _ READ(PressureSensor) OUTPUT pressure

IF pressure > maxPressure THEN OUTPUT "Open pressure valve" _____

Spot the Error

Shade in the letter of the line that contains an error.

Question 1

A p ← READ(lightSensor)

B IF p < 30 THEN

C OUTPUT "Tyre low"

D ENDIF

Question 2

A p ← READ(pressureSensor)

B IF p < 30 THEN

C OUTPUT "Tyre low"

D ENDWHILE

Question 3

A p ← READ(airPressureSensor)

B IF p < 1000 THEN

C OUTPUT Rain likely

D ENDIF

Question 4

A pad ← READ(pressurePad)

B IF pad > 0

C OUTPUT "Step detected"

D ENDIF

Question 5

A p ← READ(tankPressure)

B IF p > 200 THEN

C releaseValve ← CLOSED

D ENDIF

Answer Key

Pressure sensor

Section A: Quick Questions

A — The force applied over an area by a gas, liquid or solid

B — Pressure sensor

A — Measuring air pressure to help predict changes in the weather

B — True

A — Pressure sensor

Section B: Match the Pairs

pressure sensor → An input device that measures the force applied over an area by a gas, liquid or solid

tyre pressure monitor → A pressure sensor inside a tyre that warns the driver when the air pressure is too low

A weather station uses a pressure sensor to measure air pressure for weather forecasting → IF airPressure < 1000 THEN OUTPUT "Storm likely"

A pressure pad sends a reading to the microprocessor when someone steps on it → IF padPressure > 0 THEN SoundAlarm()

A pressure sensor measures the temperature of the air in a tyre → A pressure sensor measures pressure (force over an area), not temperature. A temperature sensor measures how hot or cold something is.

Pressure sensors can only measure the pressure of gases → Pressure sensors can measure the force applied by a gas, a liquid or a solid, for example in industrial processes and pressure pads.

Section C: Definitions

pressure sensor — An input device that measures the force applied over an area by a gas, liquid or solid, e.g. in tyre pressure monitors, weather forecasting and pressure pads.

Section D: Fill in the Blanks

IF tyrePressure < 30 THEN
   OUTPUT "Low tyre pressure"
ENDIF

IF padPressure > 0 THEN
   OUTPUT "Person detected"
ENDIF

// Weather station air pressure reading
pressure ← READ(PressureSensor)
OUTPUT pressure

pressure ← READ(PressureSensor)
OUTPUT pressure

IF pressure > maxPressure THEN
   OUTPUT "Open pressure valve"
ENDIF

Section E: Spot the Error

A — A tyre pressure monitor needs a pressure sensor, not a light sensor. The line should read from pressureSensor.

D — An IF statement must be closed with ENDIF. ENDWHILE closes a WHILE loop, and there is no loop here.

C — Text to be displayed must be in quotation marks. It should be OUTPUT "Rain likely".

B — An IF statement needs the keyword THEN after its condition. It should be IF pad > 0 THEN.

C — When the pressure in the tank is too high, the microprocessor should make the actuator OPEN the release valve to lower it. Closing it would let the pressure keep rising.