Multichannel Systems PH01 Manual - Manual (Page 8)

PH01 Manual
6
33.5
34
34.5
35
35.5
36
36.5
37
500 1000 1500 2000 2500 3000 3500 4000 4500
tem
per
a
tu
re [
°C
]
flow [µl/min]
7. Set the inflow rate to the optimum operating range (500 μl/min to 4500 μl/min). Make sure the
programmed outflow rate of the aspiration system is identical (or slightly higher) than the
inflow rate. For example, you can use a double-head peristaltic pump, and use one channel of
the pump for the input and the other for the output. An alternative would be a push-pull
pump that holds paired syringes, with one syringe for the inflow and one for the outflow.
8. Carefully double-check the setup. Make sure all perfusion lines are tight and set up properly.
9. Switch on the pump. Again, check that the outflow rate matches the inflow rate.
10. Switch on the temperature controller.
11. Check the temperature of the flow stream. Adjust the setpoint temperature accordingly. See
also chapter Temperature Control.
2.3 Flow Rate Dependent Temperature Offset
The following temperature curve shows the deviation of the setpoint and the actual liquid
temperature, depending on the flow rate. This gives you a hint on how to adjust the setpoint
temperature. For example, if you have a flow rate higher than 4000 μl/min, you will need to set
the setpoint temperature to 37.7 °C if you want to achieve an actual temperature of 36.7 °C at
the cannula tip. Please note that the actual temperature needs to be verified empirically for
each perfusion setup.
Fig. 1 Actual temperature of the fluid stream, measured at the cannula tip for different
flow rates with a setpoint temperature = 36.7 °C and an ambient temperature = 24 °C.
Note: For flow rates > 1000 μl/min and < 2500 μl/min, the temperature at the outlet is
36.2°C (
 0.1°C) with a given setpoint of 36.7°C.
For flow rates lower than 1000 μl/min, the difference between setpoint and actual
temperature is due to the temperature loss along the cannula itself, which depends on the
ambient temperature.