Automatic exposure control

SENTINEL automatic expoosure control, code TAN957

The automatic exposure control is a motorised control unit which, on command, positions a gamma ray source to expose a radiograph and retracts the source after a preset exposure time has elapsed.
The system can be fitted to most SENTINEL source projector systems.*

Features

Saving in labour costs

A single radiographer can operate a number of radiographic stations since the operator is only required to activate the automatic sequence on each one.

Consistent

Extremely precise timing of exposures and simplicity of operation for good consistent radiography.

Two part control unit

The drive unit is a steel cabinet intended to be free standing or wall mounted. It contains a reversible motordrive and handcrack assembly and is desgined to be coupled to a SENTINEL source projector.
The operator console will normally be supplied fitted to the top of the motor drive unit. Indicator lights on the face of the console tell the operator whether the source is stored, exposed or in transit. The console may, on request, be seperated from the drive unit and mounted remotely.

Interlocked to alarm systems

The design includes circuitry which may be interlocked to alarm systems such as warning horns, flashing light beacons and vault door switches.

Source retraction

The system also features an instant reverse motor which allows immediate retraction of the source, either manually or through the use of interlock switches. In addition an overload sensor is included to prevent damage if the motor stalls. A handwheel is provided to retract the source manually in the case of a power failure and a key operated power switch prevents use by unauthorised personnel.

Installation

Experienced personnel can be provided, at additional cost, for the installation of the automatic exposure control and operator training. SENTINEL also provides drawings for the pre-installation preparation and welcomes the opportunity to provide complete radiographic station design services.

Licensing

An application for licence or licence amendment should include a description of the facility and the make and model number of the sytem components.

Specifications

Exposure timing

The unit is supplied with an electronic timer, for automatic exposure timing, with a full scale range of 999.9 minutes and a settable resolution of 6 seconds. Timing accuracy and reproducability and ±1 second. Timing ranges of 999 seconds and 999 hours are available to special order.

Operator console

Length: 400mm (16 3/16in).
Width: 200mm (7 7/8in).
Height: 114mm (4 1/2in).
Weight: 7kg (15lb 8oz).

Drive unit

Length: 400mm (16 3/16in).
Width: 200mm (7 7/8in).
Height: 210mm (8 1/4in).
Weight: 115 volts: 16kg (351b 8oz).
240 volts: 19kg (42lb 8oz).

Source travel speed

0.71 m/sec (28in/sec).

Safety interlocks

Terminals provided for connection to switches on radiation area access doors, alarm horn, preliminary horn and warning lights.

Controls

Power (key switch).
Project (source).
Retract (source).
Exposure time selector.
Overload reset.
Indicator lights for power source position and overload.

Power requirements

115 volts AC, 60 Hz, 3 amp or 240 volts AC, 50 Hz, 2 amp (this must be specified when placing order) plus power for warning lights and horns.

*Note: The TAN957 can only be used with projectors that have been fitted with the necessary electrical connections and switches. Projectors that have been converted are identified by an E suffix e.g. 660B becomes 660BE. It is possible for SENTINEL to adapt equipment using the TANE957 modifictation kit. Other items of SENTINEL equipment will also be needed. Please enquire for details.