ATMOS - Pipette Accuracy Tester
ATMOS revolutionizes the way you monitor pipette accuracy.
2 Models to cover most used pipette types :
Atmos 1000: P20 to P1000 pipettes, minimum volume at 2µl
Atmos Multi *: P20 to P1250, 8 channels pipettes, P20 to P1000
- Direct measurement, no need of liquid
- Easy to use, compact (can be placed at the bench)
- Pipette accuracy monitoring done in less than 30 seconds
- pipette check protocol done in less than 3 minutes, complementary to ISO 8655-2 procedure
- Upload the calibration check report to a computer or direct print with Bluetooth mini-printer (optional)
FREQUENTLY ASKED QUESTIONS
1) Can I use ATMOS to calibrate my pipettes ?
The ISO 8655-2 norm for pipette calibration is based on gravimetry or dilution. ATMOS is an alternative method which is in principle as accurate (see note 3 below), but not yet part of the ISO 8655-2 standard. The best use of ATMOS for daily monitoring of the accuracy of your pipettes.
It will detect any change of calibration that may, for example, be related to a shock (fall on the floor) or forcing the dial beyond the limit. This allows you to put damaged pipette on hold and not use them until your next campaign of calibration by gravimetry.
It is of course also possible to use ATMOS to readjust a pipette in case of shift of accuracy (most of pipettes have a special tool to adjust the volume). This is much easier than gravimetry.
2) What is the leak measurement ?
ATMOS is measuring the air leak of the pipette or of the tip during its function. High leak can be related to a damaged piston in the pipette or to a defect in connection of the disposal tip.
The leak value is give in percentage of volume loss per second. A leak of less than 1% is acceptable.
The leak affects the accuracy of the pipette, especially when using viscous liquid. Therefore, a pipette with a leak should be serviced (grease the piston and check tip cone connection). ATMOS will indicate wrong results when the pipette is leaky.
3) How ATMOS accuracy compares with gravimetry method in ISO 8655-2 standard ?
The random error of ATMOS readings are similar to those observed in gravimetry measurement with a laboratory scale.
The absolute accuracy of ATMOS stay within ½ of the ISO 8655-2 standard. ATMOS is measuring the true volumetric displacement of the piston in the pipette. When aspirating liquid in the pipette tip, the liquid height in the tip creates a negative pressure that is slightly lowering the effective volume of aspirated liquid.
Therefore, ATMOS is using a compensation algorithm. The compensation algorithm is based on the use of standard disposable tips. When calibrating by gravimetry your pipettes with special tips, such as long tips, ATMOS reading value may differ.
4) Does the ATMOS need re-calibration service ?
ATMOS is measuring the volume dispensensed by the pipette by comparing with an internal fixed volume cavity. This comparison is done by measuring the pressure change when opening a valve towards a fixed reference volume.
Since this reference volume has no moving parts and is made of stainless steel, it cannot change with time. Therefore, the ATMOS does not need re-calibration for it internal reference.
The pressure is measured by a precision pressure microsensor, which is factory calibrated. According to the long-term drift specifications of the sensor, we estimate that the ATMOS reading will stay within its specified accuracy during more than three years. Even after this time, we don’t anticipate substantial drift.
However, considering the stability concerns of our customers, we propose an instrument check service. If the ATMOS is sent to us, we will test it on our factory calibration bench and adjust the calibration value in the software when necessary. This service cost CHF 300.- (+ shipping and tax).
5) Is it possible to export data ?
ATMOS is designed to be compatible with automated platform and can be interfaced to any computer system (Window, Mac, Linux or other). Connection to the microUSB port allows a direct interface that can be used for pipette calibration. ATMOS microUSB is connected to the industry standard CP2102 from Silicon labs.
The program ReadATM (Mac OSX and Windows) allows extraction of data (see download section of this page).
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