science

Solenoid voltmeter

Solenoid voltmeter is a science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Solenoid voltmeter rather than just read about it. In short: A solenoid voltmeter is a specific type of voltmeter electricians use to test electrical power circuits. It uses a solenoid coil to attract a spring-loaded plunger; the movement of the plunger is calibrated in terms of approximate voltage.

Key takeaways

Solenoid voltmeter belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Solenoid voltmeter to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Solenoid voltmeter from memory before moving on to harder problems.

Reference excerpt

A solenoid voltmeter is a specific type of voltmeter electricians use to test electrical power circuits. It uses a solenoid coil to attract a spring-loaded plunger; the movement of the plunger is calibrated in terms of approximate voltage. It is more rugged than a D'arsonval movement, but neither as sensitive nor as precise. Wiggy is the registered trademark for a common solenoid voltmeter used in North America derived from a device patent assigned to the Wigginton Company, US patent number 1,538,906.

Operation Rather than using a D'Arsonval movement or digital electronics, the solenoid voltmeter simply uses a spring-loaded solenoid carrying a pointer (it might also be described as a form of moving iron meter). Greater voltage creates more magnetism pulling the solenoid's core in further against the spring loading, moving the pointer. A short scale converts the pointer's movement into the voltage reading. Solenoid voltmeters usually have a scale on each side of the pointer; one is calibrated for alternating current and one is calibrated for direct current. Only one "range" is provided and it usually extends from zero to about 600 volts. A small permanent magnet rotor is usually mounted at the top of the meter. For DC, this magnet flips one way or the other, indicating by the exposed color (red or black) which lead is connected to positive. For AC, the rotor simply vibrates, indicating that the meter is connected to an AC circuit. Another form of tester uses a miniature neon lamp; the negative electrode glows, indicating polarity on DC circuits, or both electrodes glow, indicating AC. Models made by some manufacturers include continuity test lights, which are energized by a battery within the tester. This is particularly advantageous when testing, for example, fuses in live circuits, since no switching is required to change from continuity mode to voltage detecting mode.

Comparison with moving coil meters Solenoid voltmeters are extremely rugged and not very susceptible to damage through either rough handling or electrical overload, compared with more delicate but more precise instruments of the moving-coil D'arsonval type For "go/no go" testing, there is no need to read the scale as application of AC power creates a perceivable vibration and sound within the meter. This feature makes the tester very handy in noisy, poorly illuminated, or very bright surroundings. The meter can be felt, the more it jumps the higher the voltage. Solenoid voltmeters draw appreciable current in operation. When testing power supply circuits, a high-impedance connection (that is, a nearly open-circuit fault such as a burned switch contact or wire joint) in the power path might still allow enough voltage/current through to register on a high-impedance digital voltmeter, but it probably can't actuate the solenoid voltmeter. For use with high impedance circuit applications, however, they are not so good, as they draw appreciable current and therefore alter the voltage being measured. They can be used to test residual-current devices (GFCIs) because the current drawn trips most RCDs when the solenoid voltmeter is connected between the live and earth conductors. Some manufacturers include a continuity test lamp function in a solenoid meter; these use the same probes as the voltage test function. This feature is useful when testing the status of contacts in energized circuits. The continuity light displays if the contact is closed, and the solenoid voltmeter shows voltage presence if open (and energized). In contrast to multimeters, solenoid voltmeters have no other built-in functions (such as the ability to act as an ammeter, ohmmeter, or capacitance meter); they are just simple, easy-to-use power voltmeters. Solenoid voltmeters are useless on low-voltage circuits (for example, 12 volt circuits). The basic range of the voltmeter starts at around 90V (AC or DC). Solenoid voltmeters are not precise. For example, there would be no reliably perceptible difference in the reading between 220 VAC and 240 VAC. They are meant for intermittent operation. They draw a moderate amount of power from the circuit under test and can overheat if used for continuous monitoring. The low impedance and low sensitivity of the tester may not show high-impedance connections to a voltage source, which can still source enough current to cause a shock hazard.

Illustrations

Worked examples

Example 1 — a first encounter with Solenoid voltmeter

Start with the simplest possible case. Write down what Solenoid voltmeter claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Solenoid voltmeter before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Solenoid voltmeter ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Solenoid voltmeter

In research: Solenoid voltmeter appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Solenoid voltmeter in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Solenoid voltmeter is common in secondary-school and first-year university syllabi. It links to neighbouring topics Electrical test equipment, Voltmeters, so understanding it makes those chapters shorter.
In everyday life: Look for Solenoid voltmeter outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

Ask Teacher Smith questions about this articleOpens your AI tutor with a question about “Solenoid voltmeter” →

Affiliate

Preply — study more efficiently by working with a personal tutor. 50% off.

How to study Solenoid voltmeter in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Solenoid voltmeter means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Solenoid voltmeter out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Solenoid voltmeter in simple terms?

Why does Solenoid voltmeter matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Solenoid voltmeter?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Solenoid voltmeter.