Automatic Vacuum Gas Regulating Device

The Balzers RME010 regulating valve and the RVG040 valve control unit are the components of an automatic and instantaneous regulating device for maintaining constant pressure, partial pressure or gas flow when admitting gas to a vacuum plant.   

Gas flow range is <10-4 to 50 torr litre/seconde.

Automatic regulating valve RME010

 

Control circuit

Proportional gain Vp                        5 … 150
Reset time Trn                                 0.1 … 2 s
Input signal                                      +18v, +10V, 1V, -100mV
Set point                                           0 … 1000
Output                                               RME connector to dosing valve 0 … 16V
Display                                             Dosing valve voltage 0 … 16V
 Fuse                                                            
Set Point                                           Intern or Extern
Auto close                                          shorted / open
Power display                                    LED
Power switch                                      On / Off
Power                                                 230V 50 – 60Hz

Setting the Control for gas pressure regulation

 The Automatic Vacuum Gas Regulating Device is used with a Balzers SingleGauge PKR251 and associated RVG040 Control Unit to regulate the pressure in the vacuum plant.

 The regulated pressure is set up by adjusting the SET POINT multi-tour knob on the RVG040 Valve Control Unit. The PKR215 vacuum single gauge has an analog output range of 0 … +10 V, the corresponds to the SET POINT on the RVG040.

 For example, if the SET POINT knob is adjusted to 380, the pressure will be controlled according to a proportional analog output voltage of 3.8 V on the total pressure gauge.

 On the PKR 215 Compact FullRange Gauge 3.8V corresponds to 1.0x10-5mbar.

 The gas pressure value is displayed in mbar on the TPG251 control unit.

 

 

 

For a regulated pressure of p, the set point SP shall be set to:

 

SP = 60 log10 p - 280
 SP set point
p pressure [mbar]

 

 

 

 

For gas other that air, N2, O2, CO2,

a corrective factor shall be introduced

 

RVG040       REGULATED
SET POINT    PRESSURE

                         mbar

 

 
 

200         1.0x10-8
 260         1.0x10-7
320         1.0x10-6
380         1.0x10-5
 440         1.0x10-4
500         1.0x10-3
560         1.0x10-2
 620                 0.1
680                    1
740                   10
800                 100
 860               1000


 

 

Corrective factor for gas other that air, N2, O2, CO2

Gas Type

K

Valid to

air, N2, O2, CO2

1

1000 mbar

Xe

0.4

4x10-5 mbar

Kr

0.5

2x10-5 mbar

Ar

0.8

2x10-4 mbar

H2

2.4

1x10-4 mbar

Ne

4.1

2x10-5 mbar

He

5.9

4x10-5 mbar

                       Pfeiffer singlegauge cold cathode gas dependence measurement

 

 PKR 215 Compact FullRange Gauge
 Range (air, N2)    5 x 10-9 … 1000mbar
Reproducibility    ~ +5%

                      Pfeiffer singlegauge pyrani gas dependence measurement

Setting Controller Parameters

 The control parameters Tn (reset time) and Vp (proportional gain) have to be set in a way that the control loop is stable (no oscillations!). The optimal control parameters depend on the extended control system.

High reset time and low proportional gain is the most stable control. Change the controls as following: lower the reset time and increase the voltage gain until the control circuit becomes unstable then reverse slightly the parameters, The optimum tuning depends also of the SET POINT.

 The pressure voltage from the TPG251 Single Gauge unit shall be observed with an oscilloscope, A sudden increase of the SET POINT should not induce oscillations.

 Devices tested.


Prices Euro 2'500.00 + VAT and transport

 

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