Voltage and Current Sensors

Voltage and Current Sensors

In physics and engineering disciplines, voltage and current sensors are more commonly known as voltmeters and ammeters.

A voltmeter is an instrument that measures the voltage difference, or electrical potential energy difference, between two points of a circuit. By doing so, they enable us to understand behaviors such as battery voltage, voltage drops across components, and overall circuit performance.

An ammeter is an instrument that measures the rate of the electrical current flowing through a circuit. This reading is crucial in understanding the current consumption of electrical devices and ensuring safe operating conditions.

Digital Multimeters (DMM) are a relatively new advancement in electrical monitoring technology. They are modular instruments that can measure voltage, current, resistance, or capacitance depending on the setting and connection method. While DMMs are versatile in the variables they measure, they typically can only display one measurement at a time as it is recorded. PASCO sensors improve upon this design, so sensors continuously collect and send measurements into PASCO software where you can graph and analyze the results.

In this guide, we’ll cover some of our available voltage and current sensors:

• Wireless Voltage Sensor
• Wireless Current Sensor
• PASPORT Voltage-Current Sensor
• Comparison Tables

How do Voltage and Current Sensors Work?

To measure voltage difference over a circuit component, connect the sensor in parallel across the points where voltage needs to be measured. This configuration ensures that the voltage sensor has a significantly higher resistance compared to the internal resistance of the circuit. As a result, the voltage sensor draws only negligible current from the circuit, minimizing any disturbances to the measured voltage. Modern digital voltmeters employ analog-to-digital converters to display the measured voltage accurately.

Unlike voltage sensors, current sensors are connected in series with the circuit, meaning the current flows through the ammeter itself. To avoid disturbing the measured current, ammeters are designed with very low resistance. Modern digital ammeters utilize shunt resistors and internal circuitry to convert the current into a readable value on its display.

Common Applications for Voltage and Current Sensors

• Kirchhoff’s Voltage Law
• Kirchhoff’s Current Law
• Ohm’s Law
• Faraday’s Law of Induction
• Electrochemistry
• Electrolysis Reactions
• Series and Parallel circuits
• RC and LRC circuit analysis

---

Wireless Voltage Sensor

The Wireless Voltage Sensor (PS-3211) is ideal for exploring the fundamental concepts of electricity, voltage, and basic circuits. It measures voltages up to ±15 V with built-in overload protection, and features high-speed sampling rates when used with a USB connection. When combined with the Wireless Current Sensor, students can use it to explore Ohm's Law, circuits in series and parallel, and much more.

In Engineering, voltage sensors come to the rescue when a circuit malfunctions. By identifying faulty components or potential short circuits, engineers can quickly address issues and restore proper functionality. In Chemistry, the voltage sensor helps students investigate redox reactions, electrolytic cells potentials, and impact of strength of solution on these generated potentials. By testing potential differences between two half reactions, separated by a salt bridge, students can begin to understand the driving forces behind modern batteries.

This Wireless Voltage Sensor can connect to your computer or device via USB or via Bluetooth 4.0. No interface is required. It is compatible with any device that runs PASCO software, including Mac^®, Windows^®, Chromebook™, smartphones, iPad^®, and Android™ tablets. To make a measurement, students simply open either PASCO Capstone or SPARKvue software, pair the device, and start collecting data.

When comparing Voltage Sensors, PASCO currently offers five types:

• Wireless Voltage Sensor (described above)
• PASPORT Voltage-Current Sensor
• PASPORT Galvanometer
• Voltage Sensor (unshrouded)
• Voltage Sensor (shrouded)

Jump to the tables to compare specifications like range, resolution, sample rates, and more.

Watch the video below for an overview:

Software Required for Wireless Voltage Sensor

The Wireless Voltage Sensor requires either SPARKvue or PASCO Capstone software for data collection and analysis. For more information on which software is right for your classroom, see our Software Comparison Guide.

Wireless Voltage Sensor Compatible Accessories

The Wireless Voltage Sensor needs to be plugged into a charger upon arrival before use. It can connect directly to your computer or device using Bluetooth. No interface is required. Use it in collaboration with the following PASCO products:

---

Wireless Current Sensor

The Wireless Current Sensor (PS-3212) has a wide current range that enables introductory and advanced explorations of electricity and basic circuits. Designed with user safety in mind, the sensor can be used to measure currents up to 1 A and includes built-in overload protection. Collected data can be wirelessly transmitted to computers, Chromebooks, tablets, and smartphones. When combined with a Wireless Voltage Sensor, students can explore Ohm's Law, series and parallel circuits, and much more.

Since current can only exist in a complete circuit, the Wireless Current Sensor must be part of that circuit to measure current. It is connected in series and has a very low resistance (0.1 Ω). For this reason, we do not recommend connecting it directly across a battery or other voltage source without a resistive load.

In electronics labs, current sensors are invaluable for analyzing current flow in circuits and characterizing electronic components such as resistors and transistors. Current sensors also play a vital role in preventing overloading of circuits, safeguarding electrical equipment and users from potential hazards. Current sensors in chemistry enable students to count electrons involved in driving reactions much like a scale accounts for mass in reactions. Amperage determines how many atoms are involved in a chemical reaction. Current can be used to find out how much reactant is available in a solution. Integrating currents keeps track of how much metal might electroplate, or coat, an electrode.

The Wireless Current Sensor can connect to your computer or device via USB or Bluetooth 4.0. No interface is required. It is compatible with any device that runs PASCO software, including Mac^®, Windows^®, Chromebook™, smartphones, iPad^®, and Android™ tablets. To make a measurement, students simply open either PASCO Capstone or SPARKvue software, pair the device, and start collecting data.

When comparing Current Sensors, PASCO currently offers five types:

• Wireless Current Sensor (described above)
• PASPORT Voltage-Current Sensor
• PASPORT High Current Sensor
• Current Probe
• Current Sensor

Jump to the tables to compare specifications like range, resolution, sample rates, and more.

Software Required for Wireless Current Sensor

The Wireless Current Sensor requires either SPARKvue or PASCO Capstone software for data collection and analysis. For more information on which software is right for your classroom, see our Software Comparison Guide.

Wireless Current Sensor Compatible Accessories

The Wireless Current Sensor should be plugged into a charger before use. For recording, it can connect directly to your computer or device using Bluetooth. No interface is required. Use it in collaboration with the following PASCO products:

---

PASPORT Voltage-Current Sensor

The PASPORT Voltage-Current Sensor (PS-2115) combines voltage and current sensors in one device. It can simultaneously measure voltage, current, and power, then display the collected data in the form of a digital display or graph. An audible beep can be heard when overload protection shuts down the sensor, alerting teachers and keeping students safe. The sensor will automatically reset after the high current is removed.

Its differential input enables students to measure voltage or current anywhere in the circuit, so there's no need to worry about which point is at ground. This sensor ranges ±10V and ±1A, enabling it to work with a variety of battery electronic configurations and circuits. Students can measure the voltage and current associated with RC and LRC circuits and study circuit properties for both circuits in series and in parallel.

This product requires an interface to connect to your computer or device. It is compatible with any device that runs PASCO software, including Mac^®, Windows^®, Chromebook™, smartphones, iPad^®, and Android™ tablets. To make a measurement, students simply open either PASCO Capstone or SPARKvue software and start collecting data.

Jump to the table below to compare this PASCO sensor to similar sensors based on specifications like range, resolution, sample rates, and more.

Watch the video below for an overview:

Software Required for Voltage-Current Sensor

The PASPORT Voltage-Current Sensor requires either SPARKvue or PASCO Capstone software for data collection and analysis. For more information on which software is right for your classroom, see our Software Comparison Guide.

Compatible Interfaces

A PASCO interface is required to connect the PASPORT Voltage-Current Sensor to your computer or device. We recommend the following options. For a breakdown of features, capabilities, and additional options, see our Interface Comparison Guide.

PASPORT Voltage-Current Sensor Compatible Accessories

Use this sensor in collaboration with the following PASCO products:

---

Comparison Tables

Educational voltage and current sensors don’t have to look serious to have seriously powerful capabilities. We provide user-friendly voltage and current sensors that generate live data to improve students’ contextual understanding of electrical concepts. These tables should help you to make an informed purchase.

Voltage Sensors

Sensor	Interface	Features	Purpose
Wireless Voltage Sensor	✗ No Interface Required	Bluetooth 4.0 or USB connectivity Bluetooth Maximum Sample Rate: 1 kHz USB Maximum Sample Rate: 100 kHz Range: High ±15 V; Low ±5 V Resolution: High 7 mV; Low 2 mV	A wireless sensor ends confusion about the path of the circuit Convenient to use alongside the Wireless Current Sensor Kirchhoff's Voltage Law Ohm's Law RC and LRC circuit analysis Faraday's Law of Induction
PASPORT Galvanometer	✓ Any PASPORT Interface ✓ 550 ✓ 850	Maximum Sample Rate: 1 kHz Voltage Range: ±2 V Resolution: 0.1 mV Input Impedance: 1 MΩ	Use when you need to measure small currents or voltages with high resolution Dynamic variable over-sampling greatly reduces the measurement noise at low sampling rates Useful in Resistivity Experiments
Voltage Sensor (unshrouded)	✓ 550 ✓ 850 ✓ Legacy 750/500 ScienceWorkshop Interfaces	Range with 850 Interface: ±20 V AC/DC Range with other Interface: ±10 V AC/DC Standard 4 mm banana jacks Includes two alligator clip adapters	Higher sample rates up to 10 MHz (depends on interface) Ideal for LRC circuits Tightly synchronizes with interface Sensor is automatically recognized when plugged into either the 550 or 850 Universal Interfaces
Voltage Sensor (shrouded)	✓ 550 ✓ 850 ✓ Legacy 750/500 ScienceWorkshop Interfaces	Same range as unshrouded sensor Shrouded banana jacks Shrouded alligator clips Maximum Sample Rate: 10 MHz	Designed for PASCO Interface analog channels Ideal for LRC circuits PASCO Capstone recognizes that a probe has been plugged in

Voltage and Current Sensor

Sensor	Interface	Features	Purpose
PASPORT Voltage-Current Sensor	✓ Any PASPORT Interface ✓ 550 ✓ 850	Maximum Sample Rate: 1kHz Voltage Range: ±10 V Voltage Resolution: 5 mV Current Range: ±1 A Current Resolution: 0.5 mA Maximum Common Mode Voltage: 10 V Voltage Input Impedance: 2 MΩ	Differential input enables students to measure voltage or current anywhere in the circuit, so there's no need to worry about which point is at ground Not best suited for high frequency circuits

Current Sensors

Sensor	Interface	Features	Purpose
Wireless Current Sensor	✗ No Interface Required	Bluetooth 4.0 or USB connectivity Bluetooth Maximum Sample Rate: 1 kHz USB Maximum Sample Rate: 100 kHz Range: High ±1.0 A; Low ±0.1 A Resolution: High 0.2 mA; Low 0.02 mA	A wireless current sensor ends confusion about the path of the current in the circuit Ohm's Law RC and LRC circuit analysis Electrochemistry
PASPORT High Current Sensor	✓ Any PASPORT Interface ✓ 550 ✓ 850	Maximum Sample Rate: 1 kHz Current Range: ±10 A Maximum Common Mode Voltage: 10 V Maximum Voltage without Damage: ±40 V	Use when you need to measure high currents Dynamic variable over-sampling greatly reduces measurement noise at low sample rates LED over-current indicator
Current Probe	✓ Any PASPORT Interface ✓ 550 ✓ 850	Maximum Sample Rate: up to 10 MHz (depends on interface) Internal Precision Resistor: 0.10 Ω, 3.0 W, 1.0% Current Range: ±4 A Maximum Voltage without Damage: 30 V	Ideal for LRC circuits Pairs well with high speed voltage sensor Must be paired with a UI, CI, PS voltage sensor to work Not a separate sensor
Current Sensor	✓ 550 ✓ 850 ✓ Legacy 750/500 ScienceWorkshop Interfaces	Maximum Sample Rate: up to 10 MHz (depends on interface) Maximum Current Input: 1.5 A Maximum Differential Voltage: 1.5 V Maximum Common Mode Voltage: 10 V Resolution: 5 mA (1X gain), 0.5 mA 5-pin DIN on box	Study resistance, voltage and capacitance in circuits

Related Product Bundles

Do more activities with circuits in your classroom!

Additional Resources

If you have additional questions regarding our equipment or software, contact PASCO Technical Support. We're here to help.

Authored by: Sophie Guzules