Diagnostics (UltiMate 3000 Series)
Viscosity Measurement (NCP-3200RS/NCS-3500RS) - Classic Flowmeter

The following information applies only to NC pumps equipped with a Classic flowmeter.

To be able to use a certain solvent with the NC pump of the NCP-3200RS or NCS-3500RS, the solvent viscosity must be known and set correctly. The viscosity of the most common solvents (e.g., Water, Acetonitril) and solutions (e.g., Water and Acetonitril 50:50 (V/V) or 20:80 (V/V)) is available in Chromeleon and can be set, for example, in the Commands dialog box for the NC pump under %A_Viscosity and %B_Viscosity. Only if the viscosity is set correctly, the NC pump can deliver exact flow rates and gradients.

If the viscosity for the solvent that you are using is not yet available in Chromeleon, follow the steps below to establish and save additional viscosity values.

 Notes:  

It is not possible to calculate the viscosity of premixed solvents from the viscosities and mixing ratio of the components. Make sure to establish viscosity values only as described below.

The viscosity values are relative and refer to water at 42 °C.

To establish the viscosity

1. On the Control menu, select Diagnostics, and then select Viscosity Measurement.

   –or–

   On the panel tabset for the device, in the NC Pump section, click the More Options button. In the Viscosity Measurement section, click the Start button. A wizard guides you through the procedure.

   Note: During viscosity measurement, a Viper capillary needs to be connected to the flow meter outlet (an appropriate Viper capillary is provided in the accessories kit of the module). Dispose of any leaking liquid that appears at the free end of the capillary,e.g., by using a tissue.

2. On the last wizard page, click Apply to save the viscosity to the pump. The value will be used as the current value until you save a different value or change the setting in Chromeleon.

3. Write down the value if you want to use it later again or if you want to add it to the viscosity list in Chromeleon.

To change the viscosity value stored in the pump

If you want to change to a different solvent for which the viscosity has already been established as described above, proceed as follows:

1. Open the Commands dialog box for the NC pump.

2. Select %A_Viscosity (or %B_Viscosity) and type the value in the input box. The value will be used only until you establish and save a new value or enter a different value in Chromeleon.

Tip:

If you need to change solvents frequently, it may be more convenient to store the relevant viscosity values in the viscosity list which is provided, e.g., in the Commands dialog box for the NC pump under %A_Viscosity and %B_Viscosity. This ensures that values are readily available when you need them. For details, refer to Editing the Viscosity List (NCP-3200RS/NCS-3500RS).

For general information, refer to

 Diagnostics (UltiMate 3000 Series) and

Diagnostic Tests for UltiMate 3000 Instruments

Also refer to the Operating Instructions of the NC pump / NCS system shipped with the instrument.