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Our products and solutions can be used in a variety of industries and applications. Due to our vast experience and the diversity of systems, we are able to offer tailored solutions for each individual application.

Accurate, continuous and touchless measurement


The measuring principle

The DT-9300 is a transmission meter. The radiation source sends a collimated gamma ray towards the detector. The intensity of the beam is dampened by the mass in the radiation orbit. The detector detects the residual amount of gamma radiation, which is not absorbed by the matter inside the tube. Attenuation is proportional to the mass of the radiation orbit.

Radiation sources

S-Tec normally uses sources based on the Cs-137 isotope in its cs- 137 device meters have a half-life of 30 years, thereby ensuring good functionality over a long period of time. Source activity is adapted to each application, within the range of 0.1-37 GBq (3-1000 mCi).

Gamma radiation from the Cs-137 isotope is relatively insensitive to variations in the composition of the measuring medium. In special cases, other radiation sources can be used.


S-Tec normally uses organic (plastic-based) scintillators as detectors. The reason is their resistance to physical stresses such as shock and vibration, as well as good temperature and aging stability. The default ambient temperature range is -20-+50 ºC. Detectors that can withstand temperature ranges -40-+90 ºC can be supplied. Since the detector sits on the outside of the pipe, the pipe wall can be insulated against the detector for reducing heat radiation in applications with high media temperature. A significant number of supplied detectors are still operational, after 25 years of operating time.

Crystal-based detectors are used in some types of applications.


Meters from S-Tec use modern microprocessor-based electronics, with their own design of hardware and software. Experience from a large number of installed units documents a long service life and few faults. The meter is self-regulating, and in comparison tests has shown high stability during temperature variations. S-Tec offers an upgrade to DT-9300 electronics to customers who have the previous DT-9100 in operation. In most upgrades of this type, the originally delivered detector is retained. The DT-9300 has a supply voltage of 24 VDC, and an energy consumption.
Communication Standard communication is 4-20 mA superimposed Hart, and RS 485. Adaptation to bus solutions can be carried out.


Meters based on DT-9300 electronics/detector are supplied in a number of variants.

This includes applications in land-based industry, as well as in oil/gas extraction, both above and below the water surface. The measurement principle is well suited for use in density measurement sub-sea, and as an important part of integrated measurement systems for multiphase quantity measurement (this should be a keyword).

Some markets have special design requirements for equipment to be used in explosive environments. S-Tec today supplies aluminium, acid-resistant steel and duplex alloys. The DT-9300 series includes devices that have Ex certification in accordance with ATEX, IEC and FM specifications.

Update time requirements will vary with different applications. Normal process applications operate with a time constant of 20-60 sec. For processes with fast response time requirements, the DT-9300 can be delivered with time constant down to 20 msec.

Quality and precision

The detector/electronics unit in the DT-9300 is qualified in accordance with ISO-13628-6.

Each device undergoes a comprehensive test program before it is delivered to the market.

Temperature stability
The above parameters can be improved by optimized design of the individual application.


S-Tec calculates the activity needs of applications based on customers' specifications and precision and response time requirements.