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MEASARplus for use of an array of CEMs with positive high voltage


MEASARplus is a modular electronic instrument to operate systems with multiple channel electron multipliers (CEMs) or photomultipliers (PMTs) and evaluate all output signals simultaneously by pulse counting.

It consists of a mechanical housing in 19"-subrack technology, with a module high voltage generation, pulse counting, current and charge monitoring, and one system controller module with an RS 232-interface, which may easily be translated to USB by means of an external bridging circuit, to connect the system to a host computer. The computer sets the high voltage, discriminator threshold, and measurement time. Measurements can be run by start command or automatically repeated.


High Voltage
+ 128 to + 4095
HV slope (1 bit)
±100 or ±800
Preamplifier threshold
- 3 to - 130.5, step size = 0.5
Preamplifier deadtime
15 - 30 - 60 - 100
Measurement time interval
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
max. anode current (1-15) x 1.024
  Anode bias
- 120 (±10)














Fig. 3 MEASARplus for use of a CEM array












Fig. 1 MEASARplus for use of five CEMs with positive high voltage (ion mode)
Fig. 2 ...a case for MEASAR






















































Dr. Sjuts Optotechnik GmbH


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