MEASARsolo for the use of a single CEM
Home Introduction CEM Models CEM Handling Quality Assurance Preamplifier Measurement Systems

 

 

MEASARsolo-N (negative high voltage)

MEASARsolo-P (positive high voltage)

MEASARsolo-S (switchable high voltage)

 

With MEASARsolo we offer a complete measuring system to operate single channel electron multiplier. Using the software with the unit, the high voltage for the CEM at constant bias-voltage between CEM and anode, the discriminator level and the dead time of the preamplifier and the duration and number of the measuring intervals can be programed from PC or laptop. The measured data can be saved as .txt files and inserted into an evaluation program with drag&drop. During measurement, the last 16,000 measuring data are available in real time as a bmp graphic.

If a constant source of radiation is present (such as a vacuum measuring tube), then the measurement of the Counts vs. High voltage plots can be used to check in which condition the channel electron multiplier is (position of the optimal working point, see Gain Characteristics) and if the dead time and the threshold of the discriminator are correctly selected. When the radiation source is shut off, the measurement of the dark pulse rate of the CEM preamplifier combination is possible.

The MEASARsolo is available for operation either with negative or positive high voltage (MEASARsolo-N and MEASARsolo-P) or with a switchable high voltage (MEASARsolo-S).

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Fig. 5 Typical measuring run with MEASAR. With help of the measurement Counts vs. High voltage the discriminator threshold and the correct dead time of the preamplifier can be set. The system is then correctly preset for the actual measurement.

 

 

 

 
Parameters
Model
Units
Range
         
   
MEASARsolo-N
V
- 128 to - 4095
 
High Voltage
MEASARsolo-P
V
+ 128 to +4095
   
MEASARsolo-S
V
±128 to ± 4095
 
HV slope (1 bit)
 
V/s
±100 or ± 800
 
Preamplifier threshold
 
mV
- 3 to - 130.5, step size = 0.5
 
Preamplifier deadtime
 
ns
15 - 30 - 60 - 100
 
Measurement time interval
 
ms
unlimited, stop by command, or
 
(1 to 65535) x 10
  Measurement repetitions  
unlimited, stop by command, or
     
1 to 255 automatically repeated
 
CEM overload protection
MEASARsolo-N&S
µA
max. anode current (1-15) x 1.024
 
MEASARsolo-P&S
cps
(1-15) x 204800
  Current measuring
MEASARsolo-N
µA
full scale = 16.38375
  Charge accumulation
MEASARsolo-N
nC
up to 335.54 µC
  Anode bias  
V
±120 (±10)
         
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 
Fig. 1 MEASARsolo is a complete measuring system for the operation of a single channel electron multiplier
 
 
Fig. 2 The interface can be switched from RS232 to USB
 
 
Fig. 3 The bias-voltage of approximately 120 V is supplied by MEASAR
 
 
Fig. 4 Bmp graphic of a residual gas spectrum measured with a quadrupol mass spectrometer and MEASARsolo-N
 
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 


Dr. Sjuts Optotechnik GmbH

Am Schlehdorn 1, 37077 Goettingen, Germany Tel. + 49 (0) 551 209 95 62, Fax. + 49 (0) 551 209 95 63