A high impedance attenuator for use in a test and measurement instrument employs compensation to adjust the low frequency attenuation to match the high frequency attenuation exhibited by the attenuator, rather than attempting to adjust the high frequency attenuation exhibited by the attenuator. An electric field is generated upon a fluid of low conductivity inside a compressor device and an enhanced thermal conduction effect is then achieved since the electric field induces current convection, migration and deformity of bubble, increases perturbation and mixture of the flow field and eliminates boiling and delay. The corrugation improves the container sidewall strength and resistance to buckling under compressive loads such as stacking of multiple containers. The cartridge holder may incorporate image magnification to facilitate viewing of the reaction chamber as it is filled.