Linear DC Analog Module

Type: RNL-03.02

Detector: compensated ionization chamber

Measuring range: 10-1110-3 A (in 8 ranges)

Neutron flux measurement in intermediate and power ranges

High voltage generators: included (positive and negative)

Computer interfacing: 

Multiline: analog and digital signals without intelligence.

RS 422 serial I/O

Powered from single power supply

The RNL-03.02. Linear DC Analogue Module is used for the measurement of currents from compensated ionization chambers. It serves for the measurement of the neutron flux in the intermediate and power range. The current from an ionization chamber, with the values of 10-1110-3 A, is fed to the equipment through a coaxial cable. A linear DC amplifier with 8 switchable ranges converts detector signal into a measurement current of 0/420 mA. The range switching is accomplished by automatic or manual manner, depending on the state of AUT/MAN signal. In manual state the range is controlled by RANGE UP or RANGE DOWN binary signals controlled electronic stepping-switch system. The TEST GEN. is controlled from TEST ON input. If this level is high, a 5 mA current is switched to the amplifier.

The positive and negative HV power supplies are built up of encapsulated circuits surrounded by current-loop driven isolated set-value controls and HV-monitoring isolation amplifiers. Both set-value control signals (HV+CNTR and HV-CNTR), and monitoring signals (HV+MON and HV-MON) are connected to RS 422 serial I/O lines.

The module is located in a double-shielded box out of the reactor vessel. It is built in massive brass housing to protect from electro-magnetic interference waves and cross coupling. This unit is installed isolated into additional die-cast aluminum housing. This insulated installation provides an additional protective screen. Maximum 200 m long cable ensures the electrical connection between the analog module and Neutron Flux Data Processor.

The primary supply of power enters the board. Transient protection from the outside world is done by fuse diode. It saves the inputs of a four-member group of isolated DC-DC converters from damages. The unit also contains an isolation amplifier-current loop function to get the primary power monitoring signal (MON POWER S) output.


Main Technical Data

Analog Part Computer interfacing
Detector Compensated Ion Chamber

Digital Inputs
-33 to 8/13 to 72 V

Meas. Range Control
Test Control

Cable Capacity Max. 10 nF Digital Output
(relay contact)
Watch Dog
Input Current Range 10-11 to 10-3 A Analogue Outputs
0/4 to 20 mA
Det Current (direct)
Det Current (D/A)
Range Monitor (D/A)
Power Supply Mon.
Measurement Ranges /Response Time

10-10 A    1 s  1.0 %
10-9 A   0,2 s 
0.5 %
10-8 A   80 ms 
0.3 %
10-7 A   15 ms 
0.2 %
10-6 A    7 ms 
0.2 %
10-5 A    7 ms 
0.2 %
10-4 A    6 ms 
0.2 %
10-3 A     6 ms 
0.2 %

Seial I/O
RS 422A

HV Setting & Monitoring
Range & Test Control
Current Outputs Mon.
Internal Test Generator 5 A / 0.5 %

Communication Protocol


High Voltage 0 to +500 V/ max. 1 mA
0 to  -500 V/ max. 1 mA
Range Control Signals RANGE UP
Accuracy 1 %


External power 18 to 33 VDC / max.30 W
Ambient temperature 0 to + 60 oC
Relative humidity Max. 90 %
Dimensions 300 mm x 160 mm x 90 mm (without external shielding box)
Mass 3 kg (without external shielding box)