Laboratory Pipette Calibration Tool
The Pipette Calibration Tool lets your lab verify pipettes in-house with the ISO 8655 gravimetric method. Technologists weigh the water dispensed at the low, mid and high volumes of each pipette's range. The tool converts each weight to volume, checks accuracy and precision against your limits and returns a clear pass or fail. Every finalized run becomes a locked calibration certificate you can keep for CAP and CLIA inspections.
It is designed for lab managers, quality leads and supervisors who want calibration records they control between vendor service visits.
The tool above is a sample build with illustrative data. Client versions are configured to each lab's pipettes, balances and SOP.
What it records
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Pipette serial number, model, volume range and location
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Balance ID, readability, calibration due date and daily check weight
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Water temperature, barometric pressure and humidity
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Every replicate weighing at each test volume
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Accuracy, precision and pass/fail for each volume and each channel
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Technician, reviewer and corrective action, with linked as-found and as-left records
How pass or fail is decided
Each weight is converted to volume with the Z factor, which corrects for the density of water at the measured temperature and for air buoyancy. Accuracy compares the mean volume with the set volume. Precision is the coefficient of variation (CV) across the replicates. Both must be within limits at every test volume. ISO 8655-2 limits are built in, and a lab can use manufacturer specifications or its own SOP limits instead.
Frequently asked questions
How often should pipettes be calibrated? Most clinical labs verify pipettes every 6 or 12 months and after any repair, adjustment or drop. Your lab defines the interval in its procedure, and the tool tracks each pipette's next due date.
What is gravimetric pipette calibration? Water is dispensed onto an analytical balance and weighed. Because the density of water at a given temperature is known, each weight converts to a precise volume. It is the reference method described in ISO 8655-6.
What balance do I need to calibrate pipettes? The balance must resolve small enough masses for your lowest test volume: 0.001 mg for volumes under 10 µL, 0.01 mg for 10 to 100 µL and 0.1 mg for larger volumes. The tool warns you if the balance recorded is not sensitive enough.
What happens when a pipette fails calibration? The record requires a corrective action before it can be finalized. After the pipette is adjusted or repaired, an as-left re-test is linked to the original as-found record so the full history stays together.
Can we use the manufacturer's tolerances instead of ISO 8655? Yes. ISO 8655-2 limits are the default, and each calibration can use manufacturer or lab SOP limits instead.
Is this the live version? The page shows a sample build with sample data; client versions are configured to each lab's pipettes, balances and procedures.
Related tools: Preventive Maintenance Tracker · Multirule QC Tool · SOP Document Control
Could you show an inspector the last calibration for every pipette on every bench? Book a 1-hour consultation or call 517-375-2670.