An application note shows an engineer how your product or service solved one real problem: the problem, the constraints, the approach, the ratings and standards that apply, the measured result and its limits. Write it from an interview with the engineer who did the work, publish it as a plain web page, and make every rating easy to copy into a specification.
What is an application note for?
It helps an engineer decide whether your product or service fits their problem. That is a different job from the other documents on your site:
| Document | The question it answers | What the engineer does with it |
|---|---|---|
| Datasheet | What are the ratings? | Checks a number |
| Application note | Will this work for a job like mine, and how? | Checks fit, copies ratings and clauses into a specification |
| Case study | Did it work for a named customer? | Builds confidence, shows it to whoever signs |
| Capability brochure | What does the firm do? | Usually not much |
Engineers look for this kind of material before they talk to anyone. TREW Marketing and GlobalSpec found that 86 percent of technical buyers seek independent sources at least some of the time, and 72 percent do at least half of the buying process online before speaking to anyone at the supplier. An application note is the closest your own site can get to the material they are looking for, because it describes a job rather than a firm.
Source: TREW Marketing and GlobalSpec, 2025 State of Marketing to Engineers, n = 1,020 and n = 792, global, checked 1 October 2026. advertising.globalspec.com
What structure do specifiers rely on?
Seven parts, in this order. Each one answers a question the engineer will otherwise have to ring you about.
- The problem. One paragraph. What was going wrong, or what needed to happen, in the customer’s words: nuisance tripping on a drive line, a UPS at end of life in a live data hall, a harmonic problem showing up after an extension.
- The constraints. The things that made it hard. Outage windows, space, an existing installation, the voltage, the standard the site works to, the budget, the access.
- The approach. What was done and why, including options considered and rejected. Engineers trust a note more when it says what you didn’t do.
- Ratings and standards. The numbers, in a table: voltages, currents, kVA, response times, tolerances, the standards and clauses that apply. This is the section a specifier copies.
- The result. What was measured afterwards, how and when. If the measurement isn’t yours to publish, say what you can.
- The limits. Where this approach doesn’t fit. Above which rating, below which outage window, in which kinds of site.
- Who to contact. A named engineer or team, with a direct line or email, not a general enquiry form.
Leave out the company history, the mission statement, the stock photos and every adjective you can’t measure. “Robust”, “cutting-edge” and “industry-leading” tell an engineer nothing and make the rest harder to believe.
How do you write for the specifier’s copy and paste?
Assume the reader will lift parts of the note into their own document. Make that easy:
- Put ratings in a table with units, not in a sentence.
- Give standards by number and, where it helps, by clause.
- Write specification-style sentences where you can: “The UPS shall be maintained to the manufacturer’s schedule with a minimum of two preventive visits a year” reads straight into a maintenance specification. Use your real terms, not that example.
- Label drawings and single-line diagrams so they make sense out of context.
- Date the note, and say which product versions it covers.
How do you interview the engineer?
The engineer who did the work knows everything the note needs and usually won’t write it. An hour’s interview is enough for one note. Questions that get the material out:
- What was the customer trying to fix, in their words?
- What made this job harder than a normal one?
- What did you consider and rule out, and why?
- What are the ratings and standards I must get exactly right?
- What did you measure afterwards, and can we publish it?
- When would you not do it this way?
- What do customers usually get wrong when they ask for this?
Record it with permission, write it up, then send the draft back for a technical check. Nothing goes out claiming a rating, a standard or a result the engineer hasn’t confirmed, and no customer is named without their agreement.
What did the 1 October results show?
On 1 October 2026 we ran eight critical power and power equipment questions a buyer might type and classified every result. Of the 46 critical power results, 37 were service firms’ own pages. Of the 28 power equipment results, 23 were specialist firms’ own pages and three were manufacturers’ own pages.
Buyer question
“power quality survey UK”
What came back
Ten of ten results were firms’ own pages offering power quality surveys, including an engineering consultancy, a power factor equipment maker and an instrument distributor.
Sources, by kind
- Own pageFirms’ own pages: 10
Our readingNothing independent ranked, compared or named any of them. A buyer choosing a surveyor has only the firms’ own descriptions of their surveys to go on.
Search results sampled 1 October 2026 through a search tool that runs from the US, not Google UK; one run. Firms described, not named. Method on /how-we-measure.
Two other questions were the same: “HV maintenance contractor UK” and “who repairs obsolete variable speed drives UK” each returned nine of nine suppliers’ own pages. Across all eight questions, only one returned any trade press, and both of those articles reported a single multinational manufacturer’s announcement.
So the pages buyers find are written by suppliers, and most of them describe the firm rather than the job. One exception stood out. On “generator maintenance contract UK”, one supplier’s dated buyer’s guide sat among the results: a page written around what the buyer needs to know, not what the firm wants to say. That is the territory an application note occupies.
Where should you publish it?
In three places, in this order.
- Your own site, as a plain web page. Not only a PDF and never behind a form. A page can be found by search engines and read by AI assistants, linked by a specifier and forwarded by a buyer. Offer the PDF as a download from the page.
- The trade press. A version written for the editor’s readers gives the buyer what your own site can’t: an independent source. Editors decide what they run, so pitch it rather than expect it.
- Directly to named accounts. Send it to the firms you want to win, with a short note on why it is relevant to them. A note nobody sends does half its job.
The checklist
Before an application note goes live, every answer should be yes.
| # | Check | Yes / no |
|---|---|---|
| 1 | Does the first paragraph state the problem in the customer’s words? | |
| 2 | Are the constraints stated, including what made the job hard? | |
| 3 | Does it say what was considered and rejected? | |
| 4 | Are ratings in a table, with units? | |
| 5 | Are standards given by number, and clause where relevant? | |
| 6 | Is there a measured result, or a clear statement of what can’t be published? | |
| 7 | Does it state the limits, where this approach doesn’t fit? | |
| 8 | Has the engineer who did the work checked and signed it off? | |
| 9 | Is it a plain web page, readable without a form or a login? | |
| 10 | Does it name a person or team to contact, with a direct line or email? |
Where to start
Pick the question your best customers ask most often and write one note for it this month. If you want to see how your current pages compare with what buyers are shown, the shortlist scorecard has a section on what a specifier can use, and the free teardown compares you with three competitors. Writing two pieces a month from your engineers’ interviews is one of the workstreams in the Pipeline Engine.
Quick answers
A short technical document that shows how a product or service solves a specific problem in a specific setting: the problem, the constraints, the approach, the ratings and standards that apply, the measured result and the limits. It helps an engineer decide whether your product fits their job, which a datasheet alone can’t do.
Long enough to carry the problem, the constraints, the approach, the ratings, the result and the limits, and no longer. If it needs a section on your company history or a paragraph of adjectives, it is too long. If a specifier can’t find the rating they need to copy, it is too short.
An application note is about one application: a real problem, solved with stated ratings and a measured result. A white paper argues a broader position, such as a trend, a method or a market change. Engineers use application notes to check fit and to write specifications; white papers rarely give them anything to copy.
Usually not. A note behind a form can’t be read by a search engine or an AI assistant, can’t be linked by a specifier, and asks an engineer for contact details before they know whether it is relevant. Publish it as a plain web page, offer a PDF copy alongside, and send it directly to the named accounts you want to reach.
Sources
- TREW Marketing and GlobalSpec, 2025 State of Marketing to Engineers, checked 1 Oct 2026.
- KS Media, Who gets named for a UPS maintenance contract in the UK? (critical power sample, 1 October 2026), checked 1 Oct 2026.
- KS Media, How we measure (method for the 1 October 2026 search samples), checked 1 Oct 2026.