Incoherent Thomson scattering (ITS) has been applied for decades for the determination of electron density and temperature in fusion plasmas. In recent years, this diagnostic approach has been increasingly extended to studies in low-temperature plasmas. In this work, the design and preliminary implementation of a new, sensitive and uniquely compact ITS platform known as THETIS is described. The diagnostic validation procedures and preliminary results obtained using a hollow cathode plasma source are described. The new tool is intended for application to a range of sources, including Hall thrusters, planar magnetrons and electron cyclotron resonance plasmas.