science

Gurley Precision Instruments

Gurley Precision Instruments 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 Gurley Precision Instruments rather than just read about it. In short: Gurley Precision Instruments, or GPI, is an ISO-9001 certified U.S. manufacturing company based in Troy, New York. History Gurley Enterprise was established by William Gurley and Lewis E.

Key takeaways

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

Reference excerpt

Gurley Precision Instruments, or GPI, is an ISO-9001 certified U.S. manufacturing company based in Troy, New York.

History Gurley Enterprise was established by William Gurley and Lewis E. Gurley in 1845, brothers who were both alumni of Rensselaer Polytechnic Institute. In 1885 Gurley started making Hydrologic equipment and in the early 1900s acquired many new fields including paper testing equipment and thermometers. During World War II Gurley won the Army-Navy ‘E’ Award for their contribution to the war effort. In the 1950s the company started producing optical encoders. During the Cold war era, Gurley manufactured gyroscopes, sextants, star trackers, theodolites, angle dividers, optical positioning systems, and various other precision guidance devices for guided missiles and for space launch vehicles. Teledyne Corporation acquired W. & L. E. Gurley in 1968. In 1993 Gurley was sold again and became Gurley Precision Instruments. The W. & L. E. Gurley Building in Troy was named a National Historic Landmark in 1983.

Units of measurement GPI has been responsible for the creation of two commonly used units of measure. These units were so named due to the association with the devices used for their measurement.

Porosity The Gurley second or Gurley unit is a unit that describes air permeability as a function of the time required for a specified amount of air to pass through a specified area of a separator under a specified pressure. Specifically, it is defined as the number of seconds required for 100 cubic centimeters (1 deciliter) of air to pass through 1.0 square inch of a given material at a pressure differential of 4.88 inches of water (0.176 psi)(ISO 5636-5:2003).

Stiffness The Gurley unit is a measure of the stiffness of a material. Since the measurement device holds a piece of material vertically and tests the force required to deflect the material a given amount. One Gurley unit is equivalent to one milligram of force , however the Gurley unit also implies measurement with this apparatus. A related unit, the Taber, is highly correlated but uses a different apparatus (manufactured by Taber Industries) for performing measurements.

References

Hutten, Irwin Marshall (2007). Handbook of nonwoven filter media (illustrated ed.). Elsevier. ISBN 978-1-85617-441-1.

GPI homepage A Dictionary of Units of Measurement Relation between Taber and Gurley Archived 2007-01-08 at the Wayback Machine

Worked examples

Example 1 — a first encounter with Gurley Precision Instruments

Start with the simplest possible case. Write down what Gurley Precision Instruments 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 Gurley Precision Instruments 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 Gurley Precision Instruments 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 Gurley Precision Instruments

In research: Gurley Precision Instruments 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 Gurley Precision Instruments 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: Gurley Precision Instruments is common in secondary-school and first-year university syllabi. It links to neighbouring topics Manufacturing companies based in New York (state), Troy, New York, United States manufacturing company stubs, so understanding it makes those chapters shorter.
In everyday life: Look for Gurley Precision Instruments 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.

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How to study Gurley Precision Instruments in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Gurley Precision Instruments 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 Gurley Precision Instruments out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Gurley Precision Instruments in simple terms?

Gurley Precision Instruments, or GPI, is an ISO-9001 certified U.S. manufacturing company based in Troy, New York. History Gurley Enterprise was established by William Gurley and Lewis E.

Why does Gurley Precision Instruments 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 Gurley Precision Instruments?

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 Gurley Precision Instruments.