Pipette Calibration | Laboratory

Two Pipettes with Pipette Calibration in the image

Calibration of SoftGrip™ pipettes is a simple procedure that requires only a single calibration key. For your convenience, a calibration key is available that fits any SoftGrip Pipette volume range or model.

A convenient feature of your Hamilton pipette is its ability to be calibrated gravimetrically in the lab. To perform calibrations gravimetrically, you will need a good analytical balance. We suggest a six place balance with an accuracy of ± 1.0 µg to calibrate pipettes of total volumes of 25 µL or less. For pipettes of 50 µL or greater, a five place balance with accuracy of ± .01 mg will be adequate. All items used to perform the calibration must be allowed to equilibrate to room temperature.

After affixing a pipette tip to your pipette, pre-wet the tip prior to taking any measurements by pipetting and dispensing distilled water at least three times.
Make ten measurements of distilled water per tip, recording the weights. Adjust the data for environmental factors.
Determine the mean and standard deviation.
Adjust the volume if necessary; (see Figure 1.)
1. Remove the calibration label and locate the calibration reference mark.
2. Remove the plunger cap and insert the calibration key.
3. Turn the calibration key clockwise to increase volume; counter-clockwise to decrease volume. Each vertical line on the calibration key is approximately 0.2% of the pipette.
4. Remove the calibration key and replace the plunger cap. Repeat the gravimetric procedure until results are satisfactory.
5. Initial and date a new calibration label, and place it on the pipette hilt.

Pipette Calibration - Step 1

Remove the calibration label. Initial and date a new calibration label to place on the pipette.

Pipette Calibration - Step 2

Locate the calibration reference mark and remove the plunger cap.

Pipette Calibration - Step 3

Insert the calibration key. Each vertical line on the calibration key is approximately 0.2% of the pipette's total volume.

Pipette Calibration - Step 4

Turn the calibration key clockwise to increase volume, counter-clockwise to decrease volume.

Volume Settings

When setting the volume on adjustable volume pipettes, start your settings from the top digit and work down. The full units are expressed in black digits. Red digits are to the right of the decimal point. The vernier scale at the bottom provides you with the least significant digit. For the 2, 10, 25 and 50 µL pipettes, and the 1 mL pipette, the red digits on the scale reading are to the right of the decimal point. For the 100, 150 and 300 µL pipettes, only the last digit, obtained from the vernier scale, is to the right of the decimal point. See below.

Pipette Volume	2 µL	10 µL	25 µL	50 µL	100 µL	150 µL	300 µL	1 mL
Color	Aqua	Purple	Forest Green	Sandstone	Violet	Ochre	Brick Red	Sky Blue
Recommended Volume Range	0.2-2 µL	1-10 µL	2.5-25 µL	5-50 µL	10-100 µL	15-150 µL	30-300 µL	0.100-1 mL
100% Volume Setting	2.000 µL	10.00 µL	25.00 µL	50.00 µL	100.0 µL	150.0 µL	300.0 µL	1 mL
Reading	200	100	250	500	100	150	300	100
10% Volume Setting	0.200 µL	1.00 µL	2.50 µL	5.00 µL	10.0 µL	15.0 µL	30.0 µL	0.100 mL
Reading	020	010	025	050	010	015	030	010
Smallest Increment of Vernier Scale*	0.002 µL	0.02 µL	0.02 µL	0.02 µL	0.2 µL	0.2 µL	0.2 µL	0.002 mL

*Although these settings are attainable, for best results it is suggested to use the pipette only within the recommended volume range.