Calibration ensures that a sensor — whether a load cell, torque sensor, or signal conditioner — operates as accurately and reliably as possible. Over time, all sensors are subject to measurement errors, which are the deviations between the actual applied load and the sensor’s electrical output. These deviations are used to generate a calibration curve (also called a characteristic curve) that defines the sensor’s behavior under load.

Without regular calibration, those errors may grow, resulting in inaccurate measurements, quality control failures, or compliance issues. Key sources of error include:

• Zero Offset (or Zero Balance): A non-zero output when no load is applied. This offset can shift over time due to environmental factors or handling and may indicate zero instability.

• Linearity (or Non-Linearity): The deviation of the sensor’s actual output curve from a perfectly straight (theoretical) line. Even in well-designed sensors, sensitivity may change across the measurement range, requiring correction through multi-point calibration.

• Hysteresis: The difference in sensor output when a load is applied vs. removed. Typically measured at 50% of full scale, hysteresis reflects how consistently the sensor responds under loading and unloading.

• Repeatability (or Non-Repeatability): The sensor’s ability to produce consistent readings under identical loading conditions. Poor repeatability suggests instability or degradation in sensor performance.

• Temperature Effects: Changes in temperature can shift both the span and the zero point of the sensor. Calibration can help quantify or correct for these thermal effects.

During calibration, we test these parameters using high-precision equipment and certified reference weights. When requested, we also provide advanced measurements such as uncertainty, third-degree polynomial fits, or as found/as left data to meet ISO, FDA, and aerospace validation requirements.

The result? A validated calibration curve — and the confidence that your measurement system is performing to spec.

FUTEK offers several calibration methods based on your application’s accuracy requirements and the sensor’s performance profile:

One-Point Calibration

This is the simplest and fastest calibration method. It adjusts for zero offset only, making it ideal for applications that require accurate readings at a single load point. One-point calibration is suitable when the sensor’s linearity is already well-characterized and stable over time. It’s also helpful for verifying output drift in older or reused sensors.

Two-Point Calibration

Two-point calibration introduces a second reference load (typically full scale) and corrects both zero offset and span (sensitivity). This method generates a straight-line output curve across the measurement range. Because many sensors exhibit linear behavior between 0% and 100% of capacity, this approach is often sufficient for general-purpose applications. It defines the linear equation:

V_out = Sensitivity × Load + Zero Offset

Five-Point Calibration (Multi-Point Curve Fitting)

For critical applications that demand high precision across a defined range, five-point calibration is preferred. This method:

• Samples output at 0%, 20%, 40%, 60%, 80%, and 100% of full scale (and again in reverse order)
• Accounts for linearity deviations, hysteresis, and repeatability
• Enables polynomial curve fitting for advanced system integration and error compensation

In most cases, five-point calibration is performed with the sensor and instrument together to represent real-world usage and achieve plug-and-play system calibration. As illustrated in the table, for a 50 lb system using a 4–20 mA amplifier, expected output values span from 4 mA (no load) to 20 mA (full load) in both directions.

It depends on the type of sensor and what is specified on its spec sheet. Please refer to the sensor's spec sheet and look for the standard calibration specified and the loading direction (tension, compression, clockwise, counterclockwise) that is offered with the sensor.

As sensors are exposed to continuous usage, aging, output drift, overload, and improper handling, FUTEK highly recommends a yearly recalibration interval. Frequent sensor recalibration helps confirm whether the sensor maintained its accuracy over time and provides a load cell calibration certificate to show that the sensor still meets specifications and prepping the measurement systems for audits.

However, when the sensor is used in critical applications and harsh environments, load cells may require more frequent calibrations. Please consult with our Recalibration Team, who will help you evaluate the most economical calibration service interval for your sensor.

A measurement system usually encompasses the sensor, instrument or signal conditioner, cabling, and connectors. A full system calibration ensures that the whole system is performing accurately as expected. Many of the system calibrations are done live and will need high-precision loads applied. Additionally, the system calibration also takes care of any connectors that may need to be soldered. Choosing a complete system calibration allows you to start using your measurement solution out of the box. A system calibration creates a plug & play solution where all connectors, cables, and instrument settings are taken care of.

Check out below a video on the “Benefits of System Calibration”:

A sensor calibration must meet the sensor’s non-linearity spec, which is found on the sensor’s spec sheet. A system calibration, which is the calibration of a sensor and a digital instrument, must meet the sensor’s non-linearity times two and is listed on a certificate as system tolerance. A note is added when a sensor, or system, does not meet the specifications.

This document explains every section of the calibration certificate and how to interpret it.

Yes, but dual-direction calibration must be done during the same session to be valid. Be sure to request this service up front.

Dual direction calibration must be performed at the same time and under the same environmental conditions and calibration setup to be effective. A dual-direction calibration service must be ordered to get valid dual-direction calibration information.

Well, we can! On-site calibration is available for select sensors and customer locations. Contact our team for details and availability.

R.O. stands for rated output and will be the sensor's capacity, the last calibrated applied load, or the electrical equivalent of those points.

NL, or non-linearity, is the maximum deviation of the observed output of the sensor calibration curve from a theoretical straight line, ranging from zero to the last calibrated loading point. The difference between these two points is displayed as a percentage of the final calibrated loaded amount or rated output.

The zero reading is to eliminate any zero offset (or load cell zero balance) and allow the span from the loading to be presented. The zero is to show that the sensor was "tared out", or that any natural zero offsets and any effect of fixtures were removed before applying loads.

Shunt is a positive change in output that is generated from an unloaded sensor when resistance is placed between the –signal and –excitation connections of the sensor. Shunt information can be used to check the health of the sensor over time and assist with setting up devices, such as DAQ systems, by providing a known output without a physical load needed.

Electrical shunt output is presented into an equivalent load amount using the slope of all directions calibrated. This supplies confirmation of what the shunt change will be if using either direction of the listed calibration information.

A2LA information is presented in a polynomial equation with applied load indicated with x and output indicated by y. The output is found by solving for y where the applied load is placed in the equation for x. The applied load is found by solving for x where the observed output is placed in the equation for y.

"As Found" information on a calibration certificate is the observed performance of the sensor, or system, as it was first received at our load cell calibration lab. "As left" information is the result after any noted adjustments that are made to help bring the sensor, or system, into the specification. "As found = as left" means that the "as found" information meets specification and no adjustments were needed to the sensor or system.

An "as found" and "as left", if necessary, are performed under the same load cell calibration service and do not incur and additional charge.

Calibration summary information may be available online using the sensor’s serial number. Please retrieve a summary of your sensor calibration data in our ““Get Help With My Product” Tool” Tool here.

We offer:

• NIST 5-point sensor certificates
• A2LA-accredited force and system calibration certificates
• Certificate of Conformance
• System calibration reports with total system error
• Instrument-only calibration reports

Each is clearly labeled and formatted to meet industry and audit standards.

NIST-traceable calibration confirms that your sensor was tested using equipment traceable to national standards. It’s widely accepted and sufficient for general use.

A2LA calibration goes a step further — it’s both NIST-traceable and formally accredited to ISO 17025 and ANSI Z540.3. This includes detailed uncertainty analysis, a third-degree polynomial equation for system calibration, and audit-ready documentation. A2LA is recommended when compliance with strict regulatory or quality standards is required.

A Certificate of Conformance (CoC) is a document that certifies the product — whether a sensor, cable, or instrument — was manufactured in accordance with its engineering drawings and has passed all required inspections during the production process. It confirms that the item meets internal quality standards and customer specifications outlined in the purchase order.

However, it’s important to note that a CoC does not contain any measurement or calibration data. It does not verify sensor performance or accuracy — only that the product was built and inspected according to design requirements. For verification of output characteristics and traceable data, a separate Calibration Certificate is required.

Standard turnaround is less than 2 weeks after we receive the unit. If the sensor has any functionality issues, additional time may be required and will be communicated by our team. If you need expedited calibration (as fast as 2 business days), please contact us to check availability.

Yes. We offer up to 2-day expedited calibration service, depending on lab available capacity, sensor type, and calibration requirements.
This turnaround is most feasible for standard load cells and basic configurations. More complex cases, like third-party sensors, system calibrations, or sensors requiring special fixtures, may require longer lead times.
Please contact our calibration team in advance to confirm availability for your specific model.

We’ll contact you promptly with findings and next steps. If calibration can’t proceed due to a fault, our tech support team will coordinate a solution.

Many labs quote  4-6 weeks. FUTEK’s default less than 2 weeks service — with 2-day expedite options — is among the fastest in the industry, with no compromise on quality.

Please include all cables that came with the sensor. If you are requiring a full system calibration, please include the instrument alongside your sensor. We do ask that you remove all fixtures from the unit prior to shipment.

A checklist of items coming in for recalibration can be found here.

It's a self-service tool where you can enter your sensor's serial number to instantly access calibration records, warranty status, product specs, and manuals. You can also use it to download certificates and even initiate a recalibration request — all in one place. Ideal for audit prep, maintenance planning, and ongoing sensor tracking.

For enterprise clients and high-volume programs, FUTEK offers blanket recalibration agreements to streamline recurring service needs. Instead of issuing a new purchase order for each sensor, customers can operate under a pre-approved blanket PO with flexible billing terms and volume-based scheduling. This eliminates administrative friction, reduces quoting delays, and accelerates turnaround.

Sensors can be sent in batches or on a rolling basis, with internal tracking tied to each serial number. Our system flags recalibration eligibility, links to prior certificates, and ensures compliance with customer-specific intervals. Blanket agreements are especially useful for QA teams managing hundreds of sensors across facilities or those preparing for periodic audits.

To set up a blanket order program, contact our Recalibration Team — we’ll guide you through the initial setup and tailor the process to match your internal workflows.