Current position > Product detail
『Coriolis Mass Flow Meter Calibration: NIST Traceable Loop Field Benchmarks』Related information(clamp on meter|electromagnetic meter|venturi meterrotameter|orifice meter|ultrasonic flow meter|mass flow meter|coriolis mass flow meter|coriolis flow meter|magnetic flow meter|magmeter flow meter|magflow flow meter|mag meter flow meter|electromagnetic flow meter|vortex flow meter|turbine flow meter|thermal mass flow meter|thermal flow meter|rotameter flow meter)
Coriolis Mass Flow Meter Calibration: NIST Traceable Loop Field Benchmarks
Quick Answer: Silver Instruments calibrates Coriolis mass flow meters against NIST traceable loop field benchmarks for liquid and gas service. A field loop calibration checks the meter zero, span, density factor, and temperature measurement under real pipe conditions. Send us your fluid, pressure in bar, temperature in °C, pipe size DN, and flow range to get a fixed quote.
Why loop calibration beats lab-only calibration for Coriolis meters
Most engineers understand lab calibration. A flow meter goes to a bench, a reference device checks the output, and the vendor issues a certificate. That works for a new meter. It does not always reflect what happens after installation in a plant in Vietnam or a desalination facility in Saudi Arabia. In practice, loop calibration on site uses the actual transmitter, wiring, DCS input card, and process temperature. That is the good part. We have seen many Coriolis meters pass a bench test and then read high by 0.4 percent because the 4-20 mA HART loop had a ground offset or the PT100 signal was not scaled in the flow computer.
NIST traceable loop field benchmarks close that gap. The benchmark device is a reference flow meter or a master prover that has a traceable calibration certificate. The calibration chain runs from the site device to a national metrology institute. For Coriolis meters, this means mass flow, density, and temperature all get checked in one pass. A loop benchmark is not just about the sensor. It includes the transmitter, the analog output, and the display scaling. That is why buyers in Australia and Nigeria ask for loop calibration before FAT and again after commissioning.
What a NIST traceable loop benchmark actually records
We record at least four values at each flow point. The first is the reference mass flow in kg/h. The second is the meter output after temperature compensation. The third is the density reading in g/cm³ or kg/m³. The fourth is the temperature reading from the PT100 or the sensor internal RTD. For high viscosity fluids above 100 cP, we also check the damping setting and the zero stability. A customer in Thailand running palm oil at 60 °C found that a fast damping time caused unstable readings at 1,200 kg/h. The meter was fine. The loop benchmark showed the output pulse was being filtered too aggressively by the PLC counter.
Field procedure we use for Coriolis calibration
Here is the thing. A field loop calibration is not a single point zero. We run a zero check first with the meter full of process fluid and no flow. Then we run three to five flow points against the reference benchmark. Typical points are 10 percent, 25 percent, 50 percent, 75 percent, and 100 percent of the operating range. Each point needs a stable reading for at least 60 seconds. We log the loop current in mA, the HART digital value, and the pulse output frequency if the site uses a batch controller. Because most Coriolis meters have a density calibration factor, we also inject a known density fluid or compare the live density against a laboratory hydrometer.
One part that engineers skip is the cable length compensation. A Coriolis meter with a remote transmitter can have a cable length of 20 m or more. If the meter was calibrated on a bench with a 3 m cable and then installed with a 30 m cable, the drive gain can shift. The loop benchmark captures that. That matters for low flow rates below 50 kg/h on a DN15 meter. A water treatment plant in Peru had a zero drift of 0.02 percent after cable routing was changed near a VFD. The reference loop picked up the offset before the operator noticed a batch error.
Which Silver Instruments Coriolis meters suit loop benchmarks
We recommend the SIC series Coriolis mass flow meter for standard liquid mass flow and density measurement. The SIC series covers DN15 to DN200 with mass flow ranges from 0 to 1,000,000 kg/h depending on fluid density. Accuracy is 0.1 percent of rate for liquids and 0.5 percent for gas. The transmitter supports 4-20 mA HART, pulse, and RS485 Modbus outputs.
_600x400.jpg)
For high pressure gas service above 40 bar, ask for the high pressure option. We have supplied SIC Coriolis meters for wellhead gas measurement in Oman at 63 bar and 45 °C. The NIST traceable loop benchmark in that case used a turbine master meter as the site reference. The Coriolis meter checked within 0.35 percent of the reference across a 10 to 1 turndown. That is not a lab story. That is a field result with the actual pipe supports and pulsation from a reciprocating compressor.
Calibration oil, water, or process fluid: what you need to know
A Coriolis mass flow meter calibration is only as good as the reference stability. We often calibrate with water for liquid meters because water has a known density and viscosity. But water does not simulate high viscosity or gas entrainment. For food plants in Malaysia running glucose syrup at 1,400 cP, we recommend a process fluid calibration or at least a density adjustment using a laboratory hydrometer. The zero stability and drive gain behave differently when viscosity is high. A loop benchmark with the actual syrup gives real numbers. It costs more. It is worth it.
Common calibration errors and how a loop benchmark catches them
We see four errors on customer sites. The first is zero set with air in the tube. The second is flow computer scaling in kg/h while the meter outputs kg/min. The third is a 4 mA trim that does not match the DCS input card. The fourth is density calibration done at 20 °C but the process runs at 80 °C. A loop benchmark catches all four before startup. In one case, a food additive plant in Mexico had the DCS reading 100 kg/h when the actual flow was 96 kg/h. The error came from a 0.4 mA offset after a lightning event. Without a loop check, the batch controller would have filled 4 percent more product into each drum.
What to send us for a fixed calibration quote
Send us your fluid name, viscosity in cP, flow range in kg/h, pressure in bar, temperature in °C, pipe size DN, and whether you need NIST traceable loop field benchmarks or a standard factory calibration. Tell us if the site reference is a mass flow meter, a volumetric prover, or a weigh scale. We will quote the SIC Coriolis meter plus calibration scope, certificate type, and freight to your nearest port. Our sales engineers reply within 12 hours.
Contact Silver Automation Instruments for Coriolis mass flow meter calibration quotes. Tel: +86-25-68650347. WhatsApp: +86-25-52155837. WeChat: +86 15365082610.
FAQ: Coriolis Mass Flow Meter Calibration and Loop Benchmarks
Does Silver Instruments provide NIST traceable calibration certificates?
Yes. Every SIC Coriolis mass flow meter can ship with a NIST traceable factory calibration certificate. For field benchmarks we send a calibration engineer with a traceable reference device or we coordinate with a local partner.
What is the typical accuracy after a field loop calibration?
For liquid mass flow we typically hold 0.15 percent of rate or better after a loop calibration. Gas accuracy depends on pressure and density. We target 0.5 percent of rate for standard gas service.
Can you calibrate a Coriolis meter for high viscosity fluids?
Yes. We calibrate for syrups, molasses, and oils above 1,000 cP. We need a viscosity value and a sample or a clear fluid reference to set the density factor.
Do you offer site calibration outside China?
Yes. Silver Automation Instruments supports customers in Southeast Asia, the Middle East, Australia, and Latin America. We can quote a site visit, a FAT loop benchmark, or a remote audit procedure.
What information do you need for a calibration quote?
Fluid name, flow range in kg/h, pressure in bar, temperature in °C, pipe size DN, output type, hazardous area class if applicable, and the type of reference available on site.