Browse through some common questions about the EASYCAL™ 4.0 Calibration Software:
| 1. | | What is accuracy, and what is precision? |
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| Accuracy is how close to a desired target value a test result is. Precision is how close a series of test results are to each other. |
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| 2. | | What do “calibration,” “gravimetric testing” and “adjustment” mean. |
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| The word calibration gets used incorrectly quite a bit, even in our own literature (we’re working on it). Calibration actually refers to the act of measuring results from an instrument, and determining its accuracy and precision. Gravimetric testing is one method of performing calibration. In the case of liquid handling instruments, it usually means the repeated weighing of dispensed amounts of distilled water (water free of impurities). Distilled water has a defined density at specific temperature and atmospheric pressure. By knowing the mass of water dispensed, it is possible to know the actual volume dispensed, and from that, determine the accuracy and precision of the instrument. Adjustment is the physical changing of the instrument that was calibrated. This can be in two ways. The conventional way is to change the volume dispensed to represent more closely the display. This requires at least two, usually more calibrations. One to check the instrument, another to check the instrument after adjustment, readjustment of the instrument if the first correction was done improperly, and so on. The second way, the way BRAND does it, is to change the display to accurately show the actual amount dispensed. This requires only one calibration, as no physical change is made to the dispensing mechanism. |
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| 3. | | Does temperature make a big difference in gravimetric testing? |
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| Yes it does. Ideally, calibrations should be done in a climate controlled room. Temperatures should be monitored by NIST (National Institute of Standards and Technology, formerly NBS - National Bureau of Standards) traceable thermometers. |
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| 4. | | Does atmospheric pressure make a big difference in gravimetric testing? |
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| Not under most cases. EASYCAL™ allows for this to be adjusted for use in extreme cases, or if required by the customer's SOP. |
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| 5. | | The volumes dispensed by my microliter pipette are very small. How can I compensate for evaporation? |
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| Capillary tubes can be placed on the balance, and the distilled water can be dispensed into them. This will reduce the surface area substantially, allowing a reading to be taken. They can be ordered from us using catalog number 708462. |
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| 6. | | Do I need to use official EASYCAL™ tubes? |
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| No. We just offer them as a service. You can purchase them in almost any laboratory supply catalog for much less. |
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| 7. | | Can my computer run EASYCAL™? |
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| Almost any PC (“IBM compatible”) that you can purchase today can run EASYCAL. Specifics are listed in the catalog. Currently there is no Macintosh version, but it may be able to run with a program like “Soft Windows”. |
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| 8. | | My balance has an RS 232 port. Do I need to transcribe the results of my weightings? |
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| Probably not. We offer interface cables to connect your PC to your balance. Check the catalog for available cables. Many balance dealers sell cables for less money than we do. We just offer them, again, as a service. |
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| 9. | | Why don't you offer cables for Mettler balances? |
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| Mettler balances communicate somewhat differently than other balances. Your best assurance that a cable will work with your Mettler balance is to purchase a cable from your Mettler dealer. |
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| 10. | | How should I calibrate my 0.1-1?L Transferpette®? |
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| Very few laboratories have the proper balances or a controlled atmosphere room required to perform a proper calibration of this pipette. Customers should be aware that many "professional calibration facilities" do not have adequate facilities and skills to perform this calibration. Two facilities who do are Bernat, Inc. in Long Island and Troemner in the Philadelphia area. |
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| 11. | | All through the catalog, it mentions that the “Standard Operating Procedure” for instrument calibration is available. I don’t want to buy EASYCAL™ to get them, how do I get one? |
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| SOP’s are available right on this website. |
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If you're having trouble finding the information you want, BrandTech Customer Service is here to help. Call us at 888-522-2726, or if you prefer, contact us online.
