When pellets containing the amino acid alanine are irradiated, stable free radicals are produced in concentration which depends on exposure.

The measured response to microwaves of the pellet placed in a magnetic field of a paramagnetic resonance spectrometer, is quantatively related to the radiation dose which the pellet absorbed.

The Tape Tab is a new approach allowing alanine pellets to remain within the primary packaging when being read using an EPR spectrometer.  This approach ensures full and constant traceability of the dosimeter.

The alanine pellets are welded between two sheets of polyethylene terephthalate.

Dose Range

The alanine pellet has a functional dose range of 0.1kGy to 70kGy (0.01kGy to 100kGy may also be achieved) which makes it ideal for almost any range of irradiation processes.


A white cylindrical pellet of alanine in a wax binder.
90.9% Amino acid L-alpha alanine
9.1% Paraffin wax


Diameter: 4.8mm+/- 0.1mm (5mm to special order)

Height: 2.8mm +/- 0.1mm

Mass: 60mg +/-2mg within overall batch, +/- 0.6mg within a lot. (standard deviation 0.3mg)


Dimensions: 150mm x 9mm

Material: polyethylene terephthalate


Each batch is verified by NPL comparison.