pH_sensor2

IDC pH sensor

The pH sensor is a smart solution for projects that work with measuring the acidity or alkalinity of solutions. It allows for easy connection via IDC connector and instant reading of pH values using micro:bit in MakeCode environment. Try measuring pH of water, compare different liquids or track changes over time while learning the basics of programming, electronics and chemistry in a fun way.
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Description

The pH sensor is a simple input module that allows for precise measurement of the acidity and alkalinity of solutions. It is ideal for water experiments, chemistry experiments, or ecological projects. Thanks to the IDC connector, you can easily connect it to the micro:bit via a universal fixture and use it in the MakeCode environment.

Specifications

Signal conversion board

  • Power voltage: 3,3 - 5,5 V
  • Output voltage: 0 - 3,0 V
  • Probe connector: BNC
  • Signal connector: PH2.0–3P
  • Measurement accuracy: ±0,1 pH at 25°C
  • Module dimensions: 42 × 32 mm (1,66 × 1,26 in)

pH probe

  • Type: Laboratory
  • Measuring range: 0 – 14 pH
  • Temperature range: 5 – 60°C
  • Zero point: 7 0,5 ±
  • Response time: <2 min
  • Internal resistance: < 250 MΩ
  • The cable length: 100 cm
  • Service life: Depends on frequency of use

Components

pH_sensor3
pH sensor

BBC MICRO:BIT V2.2

IDC Patch Cable

Universal tool

Connection

First, connect the cable to the pH sensor and then connect the other end of the cable to the first slot on the universal fixture. Make sure that no liquid splashes on the electronics during assembly or during measurement - the measuring probe may come into contact with the liquid, but the electronic part of the module must remain dry.

When connecting, the universal tool must be turned off and the micro:bit must be disconnected from the power supply. Once the sensor is properly connected to the universal tool, you can turn on the device using the power switch and start the pH measurement.

pH_univ

Program

Program for probe V1

For the sensors to function properly, calibration is necessary. The procedure for performing the calibration can be found at manufacturer's website or in the enclosed instructions.

Program for probe V2

For the sensors to function properly, calibration is necessary. The procedure for performing the calibration can be found at manufacturer's website or in the enclosed instructions.

In conjunction with the microbit, the V1 probe can only be used for measurements up to pH < 12 (12 is the maximum value). Exceeding this limit may damage the microbit.

Tasks

Task 1: Measuring the pH of various liquids

Connect the pH sensor according to the diagram and observe the readings on the display. Prepare several different liquids – for example, tap water, lemon juice, soapy water or mineral water. Record their pH and determine which ones are acidic, neutral or basic.

Task 2: Recording pH change over time

Place the probe in a liquid and observe if its pH changes over an hour. For example, in aquarium water or a pot of plant water. Record the readings every 10 minutes.

  • Have there been any pH changes? What could have caused them?
  • Is the environment stable, or does the pH value change significantly?
  • Try to draw a graph of pH changes over time.