SPC «Doza», 6, Avenue 4806, Zelenograd, Moscow, 124460, Russia
tel: +7 (495) 777-84-85, fax: +7 (495) 742-50-84


Alpha/beta radiometer UMF-2000 for low level activity measurements

Alpha/beta radiometer UMF-2000 for low level activity measurements

Low background alpha/beta radiometer with silicon detector. The radiometer is widely used for low level activity measurements by alpha and beta counting. It is recommended for measurement of gross alpha and beta activity in natural and drinking waters.



Basic complete set:

Optional equipment and service:

Procedures for sample preparation:


Planchets for UMF-2000
Four types planchets for alpha/beta radiometer UMF-2000

Detector type

semiconductor silicon detector

Detector surface area

500, 1000 mm2

Range of measured activity:

  • alpha emitting radionuclides

0,01 – 1000 Bq

  • beta emitting radionuclides

0,1 – 3000 Bq

Energy range:

  • alpha particles

3500 – 8000 keV

  • beta particles

50 – 3500 keV

Relative measurement error


Background count rate:

  • in alpha channel (detector surface area 500 mm2 , 1000 mm2)

no more than 0,001 s-1

  • in beta channel (detector surface area 500 mm2)

no more than 0,03 s-1

  • in beta channel (detector surface area 1000 mm2)
no more than 0,07 s-1

Count intervals:

  • UMF-2000 stand alone

1 – 9999 s

  • Using UMF-2000 software

up to 64535 s

Error of count intervals

no more than 0,0001 s

Thickness of lead shielding

30 mm

Power supply

220 (+10/-15%) V/50±1 Hz


337×286×190 mm


22 kg

UMF-2000 software (ver. 2.0)
Download UMF-2000 software (ver. 2.0)

Frequently asked questions about working with UMF-2000

1. What are different planchets intended for, which can be purchased along with UMF- 2000?

Historically, the UMF-2000 is the successor to the beta-radiometers UMF-1500 and UMF-3. For those radiometers planchets (plates) were used (sometimes referred to as "targets") with outside diameter 35 mm and working area of 2.5 and 4 cm2. These planchets were used for measurements of residues after radiochemical separation of Cs-137, Sr-90 and Pb-210. The new device was designed with the expectation that all procedures developed for UMF-1500 and UMF-3 will be applied for the UMF-2000 as well. However, UMF-2000 was able to solve additional measurement problem which was beyond capabilities of other radiometers. It is gross alpha and beta activity measurement in drinking water. It is this task (where planchet’s effective surface is an important factor) for which planchets with working area of 7 cm2 have been designed (for UMF-2000 with a detector area of 5 cm2) and 14 cm2 (for UMF-2000 with a detector area of 10 cm2).

2. Why UMF-2000 is manufactured with different detectors?

Initially UMF -2000 was manufactured with only one type of detector (with an area of 5 cm2), but to measure the total activity of drinking water with high salinity (greater than 0.5 g/L) such area has been insufficient to achieve desired sensitivity in terms of alpha activity. For such cases a modification of UMF-2000 was developed with a detector with large area of 10 cm2. The sensitivity of such a device for the total activity measurements of alpha-emitters in the dry residues of water samples was twice of the sensitivity with a smaller detector. However, the sensitivity for beta radiation was not changed, because increased detector area has led to an increase in noise level.
In addition to measuring the total activity, a large area detector is used to measure the activity of AFA-RMP-20 or AFA-RSP-20 air filters. When measuring filters a metal clamp ring shall be used to hold the filter on sample drawer. More information about the measurement of activity on filters can be found in the relevant section.

3. How to handle UMF-2000, so as not to damage the detector?

The radiometer UMF-2000 includes an ion-doped silicon semiconductor detector. Detectors of this type have excellent characteristics for detection of alpha and beta radiation, but are very sensitive to the slightest damages to the work surface. In order to detect alpha radiation, the thickness of the aluminium protective layer on the working surface is less than 0.2 μm. This thin coating is easily destroyed by mechanical impact or chemical exposure. Penetrations in the detector are sources of noise resulting in sufficient degradation of radiometer’s characteristics. It may be manifested as chaotic uncontrolled counts in the beta channel, significantly higher than background values. Damaged detector should be replaced.
With the intent to protect the detector radiometer’s design does not provide user access to the detector.
Here are some simple rules that guarantee a long service life of the radiometer:

4. What is the UMF-2000 software intended for?

The UMF- 2000 software is designed to automate the processing of measurement results. It corresponds exactly to the recommendations outlined in the Operation Manual and the “Procedure for measurement of total radioactivity of water samples”. 


Back to the Section

Information ©