Calibration Services in Pomona

Four freeways, and the one that is not here

Pomona genuinely has four state facilities inside its limits, which is more than almost any city its size on this side of the county line. The SR-60, the Pomona Freeway, is named for the city and crosses its southern half. The SR-57 runs north through town to the Kellogg Interchange at I-10, and since a 2010 legislative change continues north of the 10 toward San Dimas and La Verne. The I-10, the San Bernardino Freeway, crosses the north end. And the SR-71 has a large share of its mileage inside Pomona, with exits at Rio Rancho Road, Mission Boulevard and Holt Avenue before it reaches the Kellogg Interchange. Our Tuesday and Thursday route comes in on the 57.

The freeway that is not here is the 210. Pomona borders La Verne and Claremont on the north, and the I-210 interchanges along that stretch are San Dimas Avenue in San Dimas, Foothill Boulevard and Fruit Street in La Verne, and Towne Avenue and Base Line Road in Claremont. None of them is in Pomona. The 210 is close, and some local institutions reference it in their own driving directions, but a quality manager in this city knows the difference between a freeway that serves you and a freeway you can see from the roof.

Three more worth getting right, because all three look like state routes and none of them is. Garey Avenue was the original 1934 Sign Route 71 alignment and briefly carried US-60; the segment south of US-60 went back to the City of Pomona after the Corona Expressway opened in 1958. Holt Avenue was historic US-99, US-60 and US-70, which is why the SR-71 exit list still labels it "former US 99 south." Mission Boulevard is the former US-60 east of 5th Street, and its at-grade crossing of the 71 was replaced by an overcrossing in December 2011. All three are city arterials today. Meanwhile the SR-71 Gap Closure Phase 2 project, from I-10 south to Mission Boulevard, will convert the last stretch to an eight-lane freeway and replace two railroad overheads so port containers clear; it was listed ready in September 2026 and the published completion estimates run to the end of this decade. The Metro A Line reached Pomona-North in September 2025.

Switchgear: the calibration story on this side of town

The strongest manufacturing anchor in Pomona right now is low-voltage electrical equipment. Siemens announced a $95 million, two-phase expansion of its Pomona plant in March 2025, adding a 100,000 square foot greenfield building for a site total of about 146,000 square feet and roughly 123 new jobs, with capacity aimed at the electrical infrastructure going into data centers and commercial construction. Siemens does not publish the street address, so we do not either.

Switchboard and panelboard production is one of the most calibration-dense things a factory can do, and almost none of it is dimensional. Production test requires hipot and dielectric withstand sets, insulation resistance testers, and micro-ohmmeters for busbar and bolted-joint resistance, because a four-wire Kelvin reading on a bolted joint is the only honest evidence that the joint was made correctly. Add multimeters, clamp meters, current probes and current transformers, AC and DC sources, high-current injection and primary-injection breaker test sets, thermal imagers and thermocouples for temperature-rise work, and the electrical and RF bench is carrying most of the load.

Then there is torque, which is where this industry surprises people. Every bolted electrical connection in a switchboard is a torque-controlled joint, so torque wrenches and torque screwdrivers are the highest-volume recurring item in a switchgear plant, not an afterthought. Sheet-metal enclosure and busbar fabrication adds calipers, micrometers, height gages, gage blocks and gage pins, and the powder-coat line adds pressure gauges and regulators. That is five of our nine disciplines inside one building.

Mission Boulevard, and the missile plant that is not there any more

Pomona has a defense-manufacturing legacy and no defense prime. The Convair guided missile division campus on Mission Boulevard became the General Dynamics Pomona Division and closed in 1992; Hughes Aircraft bought the missile business and moved Phalanx production to Tucson, announcing the Pomona shutdown in 1993. The federal government sold the campus, the city sold the parcels, and the old Building 2 at 1601 W Mission Blvd is now Rexford-owned warehouse and distribution space. HD Supply was named as a tenant in a September 2024 City staff report. We are not naming the other tenant from that report, because the company it named wound down its business the same month.

What the Mission and Reservoir corridor actually holds today is light industry, warehousing and job shops: machining, fabrication, plating and finishing, plus distribution operations like Impex Fitness at 2801 S Towne Ave, which the city approved for a two-phase expansion of its warehouse and office space. A machine shop in this corridor runs on gage blocks, ring, plug and thread gages, bore gages, indicators, granite surface plates and CMM artifacts, with hardness test blocks and surface-finish specimens behind them. A plating line adds bath thermometers, pH and conductivity meters, hydrometers, rectifier ammeters and coating-thickness gages with reference foils.

Distribution brings a different and often neglected list. Platform, floor and pallet scales in a commercial setting are legally sealed devices under the California Division of Measurement Standards and the Los Angeles County weights and measures program, which means accuracy there is a compliance question rather than a housekeeping one. Add mass standards, crane and hoist load cells and dynamometers for load testing, torque wrenches in the fleet shop, and temperature and humidity data loggers in climate-controlled bays.

Two hospitals, a health-sciences campus and a polytechnic

Pomona Valley Hospital Medical Center at 1798 N Garey Ave and Casa Colina Hospital and Centers for Healthcare at 255 E Bonita Ave are both licensed, operating acute-care facilities, and we will say that and stop there. We publish no bed counts, and we are not writing anything about growth at either one: the hospital announced a reduction of 265 positions in January 2026, citing reimbursement changes.

Clinical calibration is its own discipline and it is the most recurring work in this city. Pipettes, single and multichannel, verified gravimetrically, are the highest-volume item in any hospital laboratory. Around them sit centrifuge tachometers and timers, incubator, water bath, refrigerator, freezer and ultra-low freezer probes with temperature mapping, autoclave temperature and pressure verification with thermocouple loads, analytical balances with traceable weight sets, sphygmomanometers, defibrillator and electrical-safety analyzers, infusion-pump and ventilator flow analyzers, and biosafety-cabinet anemometers. CLIA, the hospital accreditation program and NFPA 99 are what make those intervals mandatory rather than optional.

Cal Poly Pomona at 3801 W Temple Ave and Western University of Health Sciences at 309 E Second St add a second instrument population: teaching and research laboratories. Engineering shops and labs run gage blocks, ring and plug gages, CMM artifacts, surface plates, universal testing machines with load cells and extensometers, torque and pressure transducers, flow meters, oscilloscopes, signal generators and spectrum analyzers, optical comparators and stage micrometers, and hardness tester test blocks. The health-sciences campus is pipette, balance and incubator work. One more piece of local furniture worth describing accurately: Fairplex at 1101 W McKinley Ave is operated by the Los Angeles County Fair Association, a private non-profit rather than a county or state agency, and the drag strip on that campus was renamed from Auto Club Raceway at Pomona.

What we will not claim about Pomona

There is no public-use airport inside Pomona city limits and we found no FAA Part 145 repair station here, so this page claims neither. Brackett Field is in La Verne, Cable is in Upland and Chino Airport is in Chino. We also could not verify a single named, currently operating AS9100-certified manufacturer, food processor or plating shop inside the city from a primary source, so we are not naming one. Pomona has aerospace and defense machining in it, feeding supply chains across the Inland Empire and the Antelope Valley, and we serve AS9100 suppliers that way rather than inventing a marquee name. Keystone Automotive was headquartered on East Bonita Avenue, but it was acquired in 2007 and is not a current Pomona employer.

On standards, two details separate a metrology lab from boilerplate. The current measurement-management standard for US defense and aerospace work is ANSI/NCSL Z540.3, with its decision-rule and test-uncertainty-ratio requirements, not the withdrawn Z540.1. And MIL-STD-45662A was cancelled a long time ago; it still appears on drawings, and we read it as a legacy callout rather than a live requirement anyone can certify to. Pomona is in the South Coast air district, which is what makes emissions, flow, temperature and pressure instrument calibration recurring on permitted combustion, coating and plating sources.

The lab is about twenty-one miles away, roughly half an hour off-peak and forty to fifty-five minutes when the 57 is working against you, on a free pickup and delivery route that runs every Tuesday and Thursday. Expedited turnaround at 24, 48 and 72 hours is comfortable at that distance, and on-site calibration covers anything that should not be moved. All nine disciplines run under one roof: dimensional, electrical and RF, temperature and humidity, pressure, mass, pipettes, force and torque, gas flow and vibration. American Gage has calibrated from inside Orange County since 1968, under current ownership since 1998, with more than a million calibrations performed in an 8,000 sq ft facility. Every certificate carries as-found and as-left data, measurement uncertainty, NIST traceability and the ANSI/NCSL Z540.3 decision rule with TUR, under ISO/IEC 17025:2017 accreditation from A2LA, certificate 4296.01. Standard turnaround is 7–10 business days.

Industries we serve in Pomona

• Electrical Equipment & Switchgear
• Machine Shops & Metal Finishing
• Healthcare & Clinical Labs
• Research & Academic Laboratories
• Warehousing & Distribution