5
Diagnostics
Testing the Pump Proportioning
46
Accela Pump Hardware Manual
Thermo Scientific
Figure 33.
Pump Status area of the Accela Pump page (ChromQuest)
3. Check the status of the Accela Pump.
4. Check the system backpressure and the pressure SD (based on pressure readings taken
over a 30 second period).
Testing the Pump Proportioning
Test the proportioning accuracy of the pump periodically by running a step gradient.
Use two eluents, methanol and spiked methanol, for this procedure. The absorbance reading
for the 100% spiked methanol solution should be in the 600 to 800 mAU range.
• If your detector contains a standard 10 mm LightPipe flow cell, prepare the spiked
methanol solution by adding 7 mg of ethyl paraben (Pump Test Mix, P/N A4904-010) to
1 L of HPLC-grade methanol.
• If your detector contains a 50 mm LightPipe flow cell, prepare the spiked methanol
solution by adding 7 mg of ethyl paraben to 4 L of HPLC-grade methanol.
Plumb your system to bypass the autosampler. Use a flow restrictor to maintain a backpressure
greater than 40 bar.
Pump status
System backpressure
and pressure
standard deviation
