Heidolph LABOROTA 4000 up to 4003 - Manual (Page 116)

Using the Laborota 4002 / 4003 control
114 Laborota 4000/4001 efficient, 4010/4011 digital, 4002/4003 control 1.02
6.4.4 p auto mode
The p auto mode combines the T auto and p const vacuum modes. T auto is
used to reach the boiling point of a solution and the pressure determined for
the continuation of the distillation is used with p const.
This has the following advantages:
- The boiling point is found automatically.
- No knowledge of thermodynamic material data is required.
Temperature sensor T auto (accessory) is installed (see chapter 4.7.1,
page 102).
Setting a value for Δp is superfluous when using the ROTAVAC vario control.
The display shows Set Δp: ----. Vacuum control is realised via the speed of the
pump.
The value of the differential gap (hysteresis) Δp indicates how much the
pressure may rise (in mbar) before the vacuum valve is opened.
High hysteresis leads to high loss rates due to increased gas transport.
Set Δp so that the valve does not activate too often.
For low boilers we recommend p values of Δ5–10 mbar, for high boilers
1–5 mbar.
Values for Set Vap only slightly higher than the constant temperature (2–15 K)
result in distillation with optimal recovery rates. Lower values lead to slower
distillation, higher rates to faster.
1. Press Mode (Fig. 6-1 (12)) until Mode p auto LED is lit.
2. Press
Select
(Fig. 6-1 (6)) until Set Vap LED is lit.
3. Use the arrow buttons (Fig. 6-1 (9)) to set the required temperature.
The setpoint temperature is visible on the display (Fig. 6-1 (8)).
4. Press
Select
(Fig. 6-1 (15)) until Set Δp LED is lit.
5. Use the arrow buttons (Fig. 6-1 (9)) to set the desired differential gap
(hysteresis) Δp.
After the start of distillation in vacuum control mode p auto, the Mode p auto
LED is lit continuously. Once the boiling point has been determined, the
Mode p const
LED also flashes.
Selecting p auto
mode