We provide comprehensive EMI/RFI environmental testing to minimize impact on electronic equipment, telemetry & diagnostic systems, communication systems, computers & CRT monitors, servers and IT networks, scientific research instruments, etc. It is important to perform an assessment if the following pertain to your facility:.
Our engineers and trained technicians maintain a high standard of quality assurance during the performance of EMI/RFI environmental testing recording EMI and RFI data in Research, Hospital, Industrial and Commercial Facilities. To read more about what your specific needs are, click on one of the services below.
Full-spectrum DC (0 Hz) to 6 GHz professional electric and magnetic field (EMF) environmental testing services of new construction sites and existing buildings, will reveal the impact of electromagnetic (EMI) and radiofrequency (RF) interference on equipment, imaging systems, and ensure conformity to various IEC/EN, FCC, and human exposure standards. Accordingly, we test non-ionizing frequencies up to 6 GHz:
Electric and magnetic field site surveys of a device, building or site (future or existing) are selected by EMF emission sources and required bandwidth:
International EMC standards (limited version):
Military compliance standards & requirements:
HEMP/EMP performance in compliance with the standards:
Do you need product emission testing on various electromechanical and lighting systems? We can provide in-house testing of fan filter units and motors, variable frequency drives (VFDs), LEDs, fluorescent, and incandescent lighting systems.
Electrical infrastructure will degrade in older buildings or due to N.E.C violations (i.e., grounded neutrals, wiring errors, etc.). Ask us how we can evaluate the building grounding plans and identify potential ground loops that can generate elevated and high magnetic fields emissions in new buildings.
Ground currents are a collective term for any errant electrical currents measured in amperes (A) that result from the natural grounding process to earth including currents on conduits, ground wires, ground rods, building steel, metal HVAC ducts, and metal water pipes (also known as plumbing currents). These ground currents normally generate magnetic fields that emanate out from a grounding conductor (ground wire, water pipe, metal HVAC duct, etc.) at a diminishing linear 1/r distance rate according to the formula: BmG = 2(I amps)/r meters. Both ground currents and plumbing currents can be easily calculated by recording the magnetic flux density at a measured distance rfeet from the source: Iamps = .15(BmG)(rfeet). However, it is much easier to use a clamp-on amp meter around a grounding conductor or water pipe (if practical) for an accurate measurement.
Net currents, also known as unbalanced or zero-sequence currents, are the vector sum of all the phase (conductor) currents. In perfectly balanced, single-circuit, three-phase transmission and distribution lines, the net current is zero when all three phase currents are equal. Theoretically, if a clamp-on amp meter could be safely placed around the three phase conductors it would measure zero amps — indicating no net current. However, if phases A and B were 1000 amps and phase C 1500 amps, there would be a measurable net current of 500 amps. This 500 amp net current produces a magnetic field that also diminishes at a linear 1/rdistance rate like a ground or plumbing current according to: BmG = 2(Iamps)/rmeters. For example, a 500 amp net, ground or plumbing current produces a 1,000 mG field at 1 meter (3.3 ft.), 500 mG at 2 meters (6.6 ft.), 250 mG at 4 meters (13.2 ft.), 200 mG at 5 meters (16.5 ft.),100 mG at 10 meters (33 ft.), and finally a 3 mG at 333.3 meters (1094 ft.). Net/Ground Current Calculator.
In commercial buildings, neutral net currents are very problematic in four-wire three-phase wye service feeders (480/277 V and 208/120 V). Ideally, when the three phases are unbalanced and there are absolutely no neutral return currents from harmonic and transient sources (reactive loads such as motors, computers, dimmers, heavy machinery, etc.) and/or errant ground/plumbing currents, the unbalanced return neutral current effectively cancels out the unbalanced phase current resulting in zero net current: if and only if the four conductors are bundled close together within the same conduit or busway. Typically, there are complex harmonic and transient components on the return neutral that generate noisy net currents. Frequently, externally produced ground and plumbing currents from nearby electrical sources leak into the return neutral via the neutral-ground bond in the switchgear and migrate back to the multiground neutral (MGN) system. The cumulative magnetic field that emanates from neutral net, ground, and plumbing currents on service feeders presents a very serious EMI threat to nearby sensitive electronic equipment and occupants.
We measure and record electric field strength (V/m) and magnetic field strength (A/m) from various RF sources from 14 kHz – 26 GHz. Including electric field, plane wave, and microwave sources:
Radio Frequency Interference (RFI), is increasingly an issue for siting sensitive instruments, communications system design and operation, and human RF exposure safety.
RF interference assessment is a requirement for:
Evaluation EMF human exposure/risk assessment standards for government and military personnel, contractors, and visitors based upon: ACGHI, NCRP, IRPA/INIRC, OSHA, WHO, DOD, and the FCC OET Bulletin 65 Evaluating Compliance with FCC Guidelines for Human Exposure to Radiofrequency Electromagnetic Fields.
See standards below:
Epoxy coated rebar testing is performed to evaluate and assess the continuity (resistance) in ohms between adjacent epoxy coated steel rebar members and uncoated rebar sections. This service is highly recommended for NMR, MRI and electron imaging facilities during pre-construction to ensure minimal ground/net current magnetic fields directly beneath EMI sensitive research tools.
For shield performance and verification testing, we use a high current and high magnetic field (1 mG up to 4,000 mG RMS) 3 phase copper bus test to expose the shielding to the predicted or simulated magnetic field environment.
When People Are at Risk
People are typically exposed to very high 50/60-Hz magnetic field levels ranging between 10-1,000 mG (milligauss) when their offices and apartments are next to, over or under transformer vaults, network protectors, secondary feeders, switchgears, distribution busways and/or electrical rooms. Usually employees and tenants are not aware of this potential hazard unless the magnetic field source compromises audio/video equipment, electronic instruments, magnetic storage media, VDT’s, computers, and networks.
Once the elevated fields are detected it ultimately becomes the responsibility of the building owner/manager to remedy, otherwise the employee and/or tenant may seek legal action. Consequently, there are only three practical solutions to mitigate magnetic field exposure produced from electrical systems within buildings: move the victims (people and equipment) away from the source, shield the source or shield the victims from the source.
Accordingly, this is a list of relevant EMF human exposure/risk assessment standards for government and military personnel, contractors, and visitors based upon: ACGHI, NCRP, IRPA/ICNRP, OSHA, WHO, DOD, and the FCC OET Bulletin 65 Evaluating Compliance with FCC Guidelines for Human Exposure to Radiofrequency Electromagnetic Fields.
Vitatech is pleased to introduce vibration and acoustic measurements to our industry leading EMI/RFI surveys. These new capabilities allow us to provide comprehensive site analysis, both pre and post development, for the Semiconductor, Nanotech and CryoEM markets. Vitatech is using the best industry standard equipment and processes to produce vibration and acoustic reports that can stand alone or be utilized by other consultants.
Most equipment that is sensitive to magnetic fields is also sensitive to noise and vibration. Multi-sensitive equipment examples are E-beam, CD-SEM, STEM and FIB tools in the semiconductor industry; MRI, Cryo-TEM in the medical field and most especially research tools like NMR, SEM, EPMA, and Aberration Corrected STEM/TEM. These tools universally have complex site requirements that demand precise and detailed planning.
Combining surveys for EMI, acoustics and vibration can streamline development, especially at the site selection and preparation phases of a project. Timely, comprehensive and accurate information allows more definitive selection of strategies. The result is better decisions made with a high degree of confidence.
