Company lists · Data refreshed November 2026

Top 25 Insulation resistance testing services based in the United States

RevenueBase identified 164 company matches for insulation resistance testing services associated with the United States as of November 2026 and tracks 4,494 professional contacts across them, including 1,869 with verified work emails. Houston is the largest hub.

This list covers company matches for insulation resistance testing services associated with the United States, found by RevenueBase SmartSearch using the meaning of business descriptions in its company graph at Exact. Ranked by professionals tracked, largest first. Rows show recorded descriptions where available, Exact search membership and the snapshot date. Data refreshed November 6, 2026.

Published by RevenueBase, a B2B data infrastructure company. This list was built with RevenueBase SmartSearch, 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 RevenueBase SmartSearch · Exact Recorded Nov 6, 2026 How this list was built
164Companies
4,494Contacts tracked
1,869Verified emails
Explore this list → Free signup · no credit card · 500 free credits

The 25 largest insulation resistance testing services based in the United States

Ranked by team size
Top 25 of 164 company matches for insulation resistance testing services based in the United States, ordered by professional contacts tracked in RevenueBase, largest first. Recorded Nov 6, 2026. The RevenueBase SmartSearch column shows Exact match membership in this saved search. Click a contact count to view that company's people. Totals use company locations recorded by RevenueBase; the displayed preview is a smaller selection.
#CompanyRevenueBase SmartSearchHeadquartersEmployeesContacts
1Exact matchIrving, OK, United StatesHQ recorded Nov 6, 20261,001-5,0001,324 contacts →

Exact match

“Shermco Industries is a provider of safe, reliable testing, repair, professional training, electrical outage planning, maintenance and analysis of rotating apparatus and…”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
2Exact matchMaryland Heights, MI, United StatesHQ recorded Nov 6, 2026501-1,000678 contacts →

Exact match

“Electric Power Systems is an independent electrical testing & engineering organization.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
3Exact matchMarlborough, MA, United StatesHQ recorded Nov 6, 2026501-1,000662 contacts →

Exact match

“Doble is the world’s most trusted brand in electrical diagnostics.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
4Exact matchKansas City, MO, United StatesHQ recorded Nov 6, 202651-200108 contacts →

Exact match

“DIT-MCO International's proven automated product testing solutions for wired assemblies provide reliable service to industrial, commercial, and military customers.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
5Exact matchFort Worth, TX, United StatesHQ recorded Nov 6, 2026201-500106 contacts →

Exact match

“For over 25 years, Sentinel-TDS, based in Dallas/Ft.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
6Exact matchSeattle, OR, United StatesHQ recorded Nov 6, 202651-20074 contacts →

Exact match

“Vision: To be the Global Power Protection Expert Mission: Deliver exceptional testing, maintenance, engineering, and commissioning services with uncompromising quality, safety…”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
7Exact matchHouston, TX, United StatesHQ recorded Nov 6, 202651-20066 contacts →

Exact match

“Zadok Technologies – Providing Engineering And Field Services To The World Quality Companies provides engineering and field services to the world.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
8Exact matchConverse, TX, United StatesHQ recorded Nov 6, 202651-20064 contacts →

Exact match

“WELCOME Power Engineering Services is an Accredited, Full-Member of the International Electrical Testing Association (NETA), and a Registered Engineering Firm in 46 states.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
9Exact matchLanham, MD, United StatesHQ recorded Nov 6, 2026201-50063 contacts →

Exact match

“ABM Electrical Power Solutions, LLC is an electrical power engineering, testing, and maintenance company based out of 4390 Parliament Pl, Lanham, Maryland, United States.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
10Exact matchFayetteville, AR, United StatesHQ recorded Nov 6, 202651-20056 contacts →

Exact match

“Welcome to Telex.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
11Exact matchRoanoke, TX, United StatesHQ recorded Nov 6, 202651-20049 contacts →

Exact match

“We rent and support electrical testing equipment.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
12Exact matchReading, PA, United StatesHQ recorded Nov 6, 202611-5048 contacts →

Exact match

“Hipotronics is the world's leading supplier of high electrical test equipment and measurement instruments.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
13Exact matchDurham, CT, United StatesHQ recorded Nov 6, 202651-20041 contacts →

Exact match

“EPST is a NETA Certified, Independent Electrical Testing & Engineering Organization.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
14Exact matchTickfaw, LA, United StatesHQ recorded Nov 6, 202651-20039 contacts →

Exact match

“At Titan we are dedicated to keeping linemen safe through quality work and excellent customer service.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
15Exact matchIndianapolis, IN, United StatesHQ recorded Nov 6, 202651-20039 contacts →

Exact match

“The talented Field engineers at HIVOLT Advanced provide electrical testing and commissioning services in a safe and reliable manner.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
16Exact matchRosharon, TX, United StatesHQ recorded Nov 6, 202651-20036 contacts →

Exact match

“Tidal Power Services specializes in delivering expert solutions and analysis for all your electrical testing, maintenance, and engineering needs.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
17Exact matchOrono, ME, United StatesHQ recorded Nov 6, 202611-5035 contacts →

Exact match

“The Snell Group’s mission is to help you leverage Infrared Thermography (IR) and Electric Motor Testing (EMT) whether your interest is condition monitoring, building applications…”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
18Exact matchTucson, AZ, United StatesHQ recorded Nov 6, 202651-20034 contacts →

Exact match

“AEA is the premier value-added innovator in the electrical power distribution industry.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
19Exact matchDecatur, AL, United StatesHQ recorded Nov 6, 202611-5032 contacts →

Exact match

“AMP Quality Energy Services performs acceptance and maintenance tests on electrical power apparatus.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
20Exact matchPortland, TX, United StatesHQ recorded Nov 6, 202651-20031 contacts →

Exact match

“We are a Texas Gulf Coast based electrical & instrumentation construction/commissioning company that specializes in electrical testing that offers a wide range of industrial…”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
21Exact matchFt. Worth, MD, United StatesHQ recorded Nov 6, 2026201-50029 contacts →

Exact match

“POWER TOGETHER.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
22Exact matchTulsa, TX, United StatesHQ recorded Nov 6, 202651-20028 contacts →

Exact match

“Sentinel Power Services, Inc.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
23Exact matchNashville, TN, United StatesHQ recorded Nov 6, 202611-5028 contacts →

Exact match

Recorded description not available.

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
24Exact matchEllsworth, KS, United StatesHQ recorded Nov 6, 202611-5023 contacts →

Exact match

“Ellsworth Electric provides comprehensive electrical contractor and insulation services for residential, industrial and commercial customers throughout Maryland, Pennsylvania…”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
25Exact matchEbensburg, PA, United StatesHQ recorded Nov 6, 202651-20021 contacts →

Exact match

“CAMCO is an independent testing and repair facility.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase

Showing 25 of 164 insulation resistance testing services based in the United States

See the full list, filter by size, metro and specialty, and access 1,869 tracked professional contacts with verified work emails. Direct dials are available where recorded.

Free signup · no credit card

View the full list →

Insulation resistance testing services based in the United States at a glance

As of Nov 6, 2026
41.6%Verified-email coverage
27.4Average contacts per company
11-50Median size (employees)
3.0%Largest-city concentration · Houston
Nov 6, 2026Page data refreshed

Companies by employee count

1-10
81
11-50
52
51-200
22
201-500
5
501-1,000
2
1,001-5,000
1

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 164 companies.

How this list was built

The recorded descriptions help you assess these company matches. Check a company’s website for its current services and locations.

Source
The RevenueBase company graph: 60 million companies and 398.9 million professional contacts resolved from primary sources, queried with RevenueBase SmartSearch, the natural-language company search available to every RevenueBase user.
What qualifies
Company records associated with the United States whose business descriptions match “insulation resistance testing services” by meaning at the Exact setting. Descriptions are compiled in the RevenueBase company graph from public websites, profiles and company information where available; they are not guaranteed quotations from the company's website.
RevenueBase SmartSearch
Describe a niche company in your own words to find businesses by meaning. Exact, Similar, Related and Broad control the breadth of RevenueBase SmartSearch. This saved list uses Exact. Each row's Exact match badge shows inclusion in that search, not an individual score or a service-quality judgment.
Public preview
The public preview omits records without a verified work email. Where headquarters information is recorded, preview rows are also filtered to this page’s location. Dataset totals and geographic summaries describe the full matched records before these preview filters.
Match quality
RevenueBase's August 25, 2026 study assessed 4,198 description/company pairs across matching settings. The publisher reports 86% good or better at Exact. This evaluates the method across queries; it does not audit this individual list. Recorded company descriptions, where available, help you judge each match yourself. Read the full methodology: how the lists are built and what the study measures.
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 displayed company carries at least one verified work email. RevenueBase tracks 1,869 professional contacts with verified work emails across the full matched dataset. 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 November 6, 2026. Lists refresh periodically as the graph is re-checked.
Record context
Company records and descriptions can change. Check the company's website for its current services and locations.

Frequently asked

What is RevenueBase SmartSearch?

RevenueBase SmartSearch finds niche companies by the meaning of their business descriptions in the RevenueBase company graph. Exact, Similar, Related and Broad control how closely companies must fit your description. This list uses Exact for “insulation resistance testing services”; each Exact match badge shows search membership, not an individual similarity or quality score.

How many insulation resistance testing services are there based in the United States?

RevenueBase identified 164 company matches for insulation resistance testing services associated with the United States as of November 2026, using the meaning of business descriptions at Exact. This is the recorded matched set in the RevenueBase company graph.

What is the largest company on this list?

Shermco Industries tops the displayed preview by professional contacts tracked in RevenueBase. Recorded headquarters appear in the company rows.

Which city has the most insulation resistance testing services?

Houston leads with 5 company records, followed by Miami (5) and Atlanta (3).

How do I get contact information for these companies?

A free RevenueBase account lets you run this exact search and work limited free results with 500 credits to start. Upgrading provides access to the 1,869 professional contacts with verified work emails tracked across these 164 companies; direct dials are available where recorded.

How current is this list?

The list refreshes periodically as the company graph is re-checked. This page's figures were pulled on November 6, 2026.

Ready to reach these companies? Verified emails and direct dials for all 164 insulation resistance testing services based in the United States. Start with a free account, no credit card.

Download this list →

Related lists

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 SmartSearch, 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.