Company lists · Data refreshed September 2026

Top 25 Electrical testing and diagnostics based in the United States

Name: Electrical testing and diagnostics based in the United States
Creator: RevenueBase
License: https://creativecommons.org/licenses/by/4.0/

Compiled by the RevenueBase Data Team Data refreshed Sep 19, 2026 2,007 companies tracked

RevenueBase identified 2,007 electrical testing and diagnostics headquartered in the United States as of September 2026 and tracks 14,921 professional contacts across them, including 4,175 with verified work emails. Houston is the largest hub.

This list covers electrical testing and diagnostics headquartered in the United States, matched on what each company actually does as described in its own words. Ranked by team size, largest first. Every row shows the company's own description, its RevenueBase Smart Search rating, and when it was last checked. Data refreshed September 19, 2026.

Published by RevenueBase, a B2B data infrastructure company. This list was built with RevenueBase Smart Search, the natural-language company search RevenueBase customers use to build their own targeted lists and unlock verified emails and direct dials at the companies on them. How these lists are built and judged.

How to read this list HQ checked on every row RevenueBase Smart Search rating on every row Refreshed Sep 19, 2026 86% judged on-target in blind review

2,007Companies

14,921Contacts tracked

4,175Verified emails

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The 25 largest electrical testing and diagnostics based in the United States

Ranked by team size

Top 25 of 2,007 electrical testing and diagnostics based in the United States, ranked by team size, largest first. Data refreshed Sep 19, 2026. RevenueBase Smart Search rates how each company's information relates to electrical testing and diagnostics: strong evidence (its own description names it), partial (names part of it), indirect (matched on the rest of its profile rather than the description shown). Click a contact count to view that company's people.
#	Company	RevenueBase Smart Search	Headquarters	Employees	Contacts
1	Shermco Industries	Strong evidence	Irving, TX, United StatesHQ checked Sep 19, 2026	1,001-5,000	1,221 contacts →
	Strong evidence “Shermco Industries is a provider of safe, reliable testing, repair, professional training, electrical outage planning, maintenance and analysis of rotating apparatus and…” Source: RevenueBase Database · checked Sep 19, 2026
2	Electric Power Systems	Strong evidence	Maryland Heights, MO, United StatesHQ checked Sep 19, 2026	501-1,000	653 contacts →
	Strong evidence “Electric Power Systems is an independent electrical testing & engineering organization.” Source: RevenueBase Database · checked Sep 19, 2026
3	Doble Engineering	Strong evidence	Marlborough, MA, United StatesHQ checked Sep 19, 2026	501-1,000	619 contacts →
	Strong evidence “Doble is the world’s most trusted brand in electrical diagnostics.” Source: RevenueBase Database · checked Sep 19, 2026
4	Mr. Electric	Partial evidence	Waco, TX, United StatesHQ checked Sep 19, 2026	1,001-5,000	308 contacts →
	Partial evidence “Residential and Commercial Services Since 1994, the professional electricians at Mr.” Source: RevenueBase Database · checked Sep 19, 2026
5	Electrical Reliability Services, INC	Partial evidence	Westerville, OH, United StatesHQ checked Sep 19, 2026	201-500	228 contacts →
	Partial evidence “In business since 1971, Electrical Reliability Services, Inc.” Source: RevenueBase Database · checked Sep 19, 2026
6	Hilscher-Clarke Electric Company	Partial evidence	Canton, OH, United StatesHQ checked Sep 19, 2026	201-500	196 contacts →
	Partial evidence “Hilscher-Clarke Electric Company is a full service electrical contractor, with more than 100 years experience in the commercial, industrial, and residential markets.” Source: RevenueBase Database · checked Sep 19, 2026
7	Sdmyers	Partial evidence	Tallmadge, OH, United StatesHQ checked Sep 19, 2026	201-500	195 contacts →
	Partial evidence “SDMyers is the industry leader in transformer and substation maintenance and electric power system reliability.” Source: RevenueBase Database · checked Sep 19, 2026
8	Gurtz Electric CO	Indirect evidence	Arlington Heights, IL, United StatesHQ checked Sep 19, 2026	501-1,000	167 contacts →
	Indirect evidence Source: RevenueBase Database · checked Sep 19, 2026
9	Varcomac LLC	Partial evidence	Odenton, MD, United StatesHQ checked Sep 19, 2026	501-1,000	158 contacts →
	Partial evidence “Today's electrical infrastructure requires a level of quality control that only the best trained and most knowledgeable electrical contractors can master.” Source: RevenueBase Database · checked Sep 19, 2026
10	Kenmor Electric Company	Partial evidence	Houston, TX, United StatesHQ checked Sep 19, 2026	201-500	152 contacts →
	Partial evidence “KenMor Electric is recognized for its service and craftsmanship.” Source: RevenueBase Database · checked Sep 19, 2026
11	Hood Patterson & Dewar	Partial evidence	Norcross, GA, United StatesHQ checked Sep 19, 2026	51-200	138 contacts →
	Partial evidence “Hood Patterson & Dewar (HP & D) is a customer-driven, employee-owned collaborative team of engineers, technicians, and service professionals, offering: • Electrical and mechanical…” Source: RevenueBase Database · checked Sep 19, 2026
12	White Electrical Construction Company	Partial evidence	Atlanta, GA, United StatesHQ checked Sep 19, 2026	201-500	132 contacts →
	Partial evidence “White Electrical is a full service industrial electrical contractor supplying many different industries including: automotive, food/beverage, power, chemical, pulp/paper…” Source: RevenueBase Database · checked Sep 19, 2026
13	Lemberg	Partial evidence	Brookfield, WI, United StatesHQ checked Sep 19, 2026	51-200	105 contacts →
	Partial evidence “About Lemberg: Lemberg is a full-service electrical contracting firm for industrial, commercial and residential customers.” Source: RevenueBase Database · checked Sep 19, 2026
14	Dit-Mco International	Partial evidence	Kansas City, MO, United StatesHQ checked Sep 19, 2026	51-200	102 contacts →
	Partial evidence “DIT-MCO International's proven automated product testing solutions for wired assemblies provide reliable service to industrial, commercial, and military customers.” Source: RevenueBase Database · checked Sep 19, 2026
15	Master Electric	Partial evidence	Savage, MN, United StatesHQ checked Sep 19, 2026	51-200	98 contacts →
	Partial evidence “Master Electric is a full service electrical contractor servicing the upper mid-west since 1973, providing commercial/industrial, multi-family, communication/data/fire/safety with…” Source: RevenueBase Database · checked Sep 19, 2026
16	United Electric	Partial evidence	Bradenton, FL, United StatesHQ checked Sep 19, 2026	11-50	98 contacts →
	Partial evidence “Welcome to United Electric Founded in 1976, United Electric has emerged as one of the leading electrical services companies in Sarasota and Manatee counties.” Source: RevenueBase Database · checked Sep 19, 2026
17	Allan Briteway Electrical Utility Contractors, INC	Partial evidence	Florham Park, NJ, United StatesHQ checked Sep 19, 2026	51-200	94 contacts →
	Partial evidence “With over 85 years of experience in the electrical contracting industry, Allan Briteway Electrical Utility Contractors, Inc.” Source: RevenueBase Database · checked Sep 19, 2026
18	Technical Diagnostic Services	Indirect evidence	Fort Worth, TX, United StatesHQ checked Sep 19, 2026	201-500	91 contacts →
	Indirect evidence “For over 25 years, Sentinel-TDS, based in Dallas/Ft.” Source: RevenueBase Database · checked Sep 19, 2026
19	Electrical Engineering & Service Co., INC	Strong evidence	Holbrook, MA, United StatesHQ checked Sep 19, 2026	n/a	91 contacts →
	Strong evidence “Specialists in Electrical Power Systems - Testing, Commissioning, Maintenance.” Source: RevenueBase Database · checked Sep 19, 2026
20	Hi-Tech Electric Company	Partial evidence	Kalamazoo, MI, United StatesHQ checked Sep 19, 2026	201-500	87 contacts →
	Partial evidence “Our licensed electricians are prepared to solve all of your complex electrical issues.” Source: RevenueBase Database · checked Sep 19, 2026
21	Electrical Power & Safety Company	Partial evidence	Medina, MN, United StatesHQ checked Sep 19, 2026	11-50	82 contacts →
	Partial evidence “Delivering Outstanding products and services for electrical power systems We specialize in performing Arc Flash Analysis of your facility and training your team to deal with this…” Source: RevenueBase Database · checked Sep 19, 2026
22	Praetorian Power Protection LLC	Partial evidence	Seattle, OR, United StatesHQ checked Sep 19, 2026	51-200	71 contacts →
	Partial evidence “Vision: To be the Global Power Protection Expert Mission: Deliver exceptional testing, maintenance, engineering, and commissioning services with uncompromising quality, safety…” Source: RevenueBase Database · checked Sep 19, 2026
23	Groves Electrical Services	Partial evidence	Madisonville, KY, United StatesHQ checked Sep 19, 2026	501-1,000	70 contacts →
	Partial evidence “Groves Electrical Services is a turnkey industrial and commercial electrical contractor taking projects from conception to completion nationwide.” Source: RevenueBase Database · checked Sep 19, 2026
24	Rowan Electric	Partial evidence	Carlsbad, CA, United StatesHQ checked Sep 19, 2026	51-200	66 contacts →
	Partial evidence “Rowan Electric was founded by brothers Paul and Mark Rowan, who have been proudly serving the greater San Diego area since 1998.” Source: RevenueBase Database · checked Sep 19, 2026
25	Capitol Valley Electric	Partial evidence	Sacramento, CA, United StatesHQ checked Sep 19, 2026	51-200	58 contacts →
	Partial evidence “Commercial & Industrial Electrical Contractor Capitol Valley Electric, Inc.” Source: RevenueBase Database · checked Sep 19, 2026

RevenueBase Smart Search

RevenueBase Smart Search assesses information from a company’s LinkedIn profile, information supplied directly by the company, its website, and other publicly available sources. It uses that information to rate how closely the company relates to this list’s category: electrical testing and diagnostics. Every row carries its rating and the description the rating was read from, so each one can be checked rather than taken on trust.

Strong evidence: The company's own public description of its business names electrical testing and diagnostics.
Partial evidence: Its own public description names part of electrical testing and diagnostics, so it works in or next to the category without describing itself that way.
Indirect evidence: The description shown does not name electrical testing and diagnostics. The match rests on the rest of the company's public profile rather than the one sentence quoted here, so this is the rating to check first.

RevenueBase Smart Search is how these lists are built: RevenueBase's data engine and AI assemble the companies that match a category defined in a user's own words, so a list can be about what companies actually do rather than about whichever industry code they were filed under.

Showing 25 of 2,007 electrical testing and diagnostics based in the United States

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Electrical testing and diagnostics based in the United States at a glance

As of Sep 19, 2026

28.0%Verified-email coverage

7.4Average contacts per company

1-10Median size (employees)

1.7%Largest-city concentration · Houston

Sep 19, 2026Page data refreshed

Companies by employee count

1-10

1,178

11-50

638

51-200

130

201-500

501-1,000

1,001-5,000

Email recency for this list is measured worldwide rather than for United States, so it is reported there. Company counts and contact totals on this page are exact for United States, over 2,007 companies.

How this list was built

Company categories are rarely black and white. RevenueBase reads each company's own description of its business to decide whether it belongs among electrical testing and diagnostics, so some rows will be adjacent to the category rather than pure plays. The description and RevenueBase Smart Search rating on every row are there so you can check each match yourself.

Source: The RevenueBase company graph: 60 million companies and 398.9 million professional contacts resolved from primary sources, queried with RevenueBase Smart Search, the natural-language company search available to every RevenueBase user.
What qualifies: Companies headquartered in the United States whose own description of what they do matches “electrical testing and diagnostics”. Matching reads each company's description, not its industry code or its name.
RevenueBase Smart Search: RevenueBase Smart Search is how this list is assembled and how each row is rated. RevenueBase's data engine and AI assess a company's LinkedIn profile, information supplied directly by the company, its website and other publicly available information, then relate it to a category defined in a user's own words. Each row is rated strong evidence (its own description names electrical testing and diagnostics), partial evidence (it names part of the category) or indirect evidence (the description shown names none of it and the match rests on the rest of the company's profile). The description supporting each rating is quoted on the row.
What we exclude: Companies whose own description does not clearly place them among electrical testing and diagnostics, and records with no verified work email. Companies headquartered outside United States are excluded even when they keep an office there.
Match quality: In blind human judging of this matching method, 86% of matched companies were on target. Expect roughly 1 in 7 rows to be adjacent to the category rather than a pure play. Every row shows the company's own description and its RevenueBase Smart Search rating so you can judge each match yourself. Read the full methodology: how the lists are built, how the judging worked, and what the figure means.
Ranking: Team size, largest first: companies are ordered by the number of professionals RevenueBase tracks at each one. Employee ranges shown are reported bands, for context.
Verification: Every listed company carries at least one verified work email, 4,175 across the full list. Contacts re-verify on a rolling cadence, and each contact's own verification date is shown inside RevenueBase.
Refresh: This page's figures were pulled from the company graph on September 19, 2026. Lists refresh periodically as the graph is re-checked.
Corrections: Wrong category, wrong headquarters, or a company that has closed? Use “Report an issue” on any row. Reports go to the RevenueBase Data Team and feed back into the company graph.

Electrical testing and diagnostics by metro

Electrical testing and diagnostics in Houston35

Frequently asked

What is RevenueBase Smart Search?

RevenueBase Smart Search is how RevenueBase decides which companies belong on this list and how strongly each one fits. Its data engine and AI assess a company's LinkedIn profile, information supplied directly by the company, its website and other publicly available information, then relate it to the category the list is about. Each row is rated strong evidence when the company's own description names electrical testing and diagnostics, partial evidence when it names part of the category, and indirect evidence when the description shown names none of it and the match rests on the rest of the company's profile.

How many electrical testing and diagnostics are there based in the United States?

RevenueBase identified 2,007 electrical testing and diagnostics headquartered in the United States as of September 2026, matched on each company's own description of what it does rather than its industry code.

What is the largest company on this list?

Shermco Industries, headquartered in Irving, tops this list with the largest team on record.

Which city has the most electrical testing and diagnostics?

Houston leads with 35 headquartered companies, followed by New York (13) and Charlotte (12).

How do I get contact information for these companies?

A free RevenueBase account lets you run this exact search and work the top results, verified emails and direct dials included. Upgrading unlocks all 4,175 verified decision-maker contacts tracked across these 2,007 companies.

How current is this list?

The list refreshes periodically as the company graph is re-checked. This page's figures were pulled on September 19, 2026.

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About this data

RevenueBase is a B2B data infrastructure company. Its company graph covers 60 million companies and 398.9 million professional contacts, with emails verified on a rolling cadence rather than scraped once and left to decay. These company lists are generated directly from that graph with RevenueBase Smart Search, the same natural-language company search every RevenueBase user has: describe a market in plain words, get the companies that match, and add verified emails and direct dials for the people at them. It is the same data that powers RevenueBase's B2B data products, and a free account includes 500 credits to start. How these lists are built and judged.