4 function of the evaporation trap – A&D Weighing FX-300i-PT User Manual

Page 7

Advertising
background image

5

NOTE For detailed information on WinCT-Pipette, refer to “How to use WinCT-Pipette.pdf” in the

WinCT-Pipette CD-ROM.

Main Window

When WinCT-Pipette starts up, the window below opens

Specifications

Enter the pipette volume, specifications of

accuracy and repeatability used for

pass/fail judgment.

Measured Values

Displays the mass values transmitted from the

balance and the volumetric values obtained

using the Z factor.

Measurement Results

Displays the measurement results and

judgment results.

1-4 Function of the Evaporation Trap

In the pipette accuracy test using the gravimetric method, to obtain the mass of the test liquid, distilled

water is dispensed from the pipette into the sample cup installed on the balance. The obtained value,

however, is generally smaller due to evaporation loss of the test liquid. To prevent evaporation of the test

liquid, the evaporation trap is used. The ISO 8655 standard recommends that the humidity of the

measurement environment be greater than 50% RH.

Water is poured into the groove of the evaporation trap. This helps to maintain the humidity inside

the evaporation trap high and reduces evaporation. Using the evaporation trap reduces the

evaporation of the test liquid to about 25% or 0.05 mg per minute, compared with the value when the

evaporation trap is not used. This yields a measurement environment where there is no need to

consider measurement errors due to evaporation loss of the test liquid.

Another function of the evaporation trap is one as a breeze break, to prevent drafts in the

measurement environment from influencing the weighing operation and enable a stable weighing.

The evaporation trap is designed for an easy dispensing of the test liquid. The upper part has a

sloped surface so that the pipette can be inserted from obliquely above.

The Z factor is automatically calculated using the values of
the distilled water temperature and the barometric pressure.

Measurement environment
Enter the ambient relative humidity,
the distilled water temperature and
the barometric pressure.

Advertising
This manual is related to the following products: