INDUS make Mc-leod gauges measures absolute vacuum in its very last stages. Model No : VCT-525, Mc-Leod Gauge, with stand & 1st fill Mercury.
This Gauge is suitable for measurement of vacuum in the range : 10 mmHG . to 0.001 Torr fitted with a stand & provided with 1st fill Pure Mercury. This gauge avoids use of a movable reservoir of mercury and also requires only about 14 cc. of mercury for first filling. The total size of this gauge is about 9” x 6”.
Gauge is portable & so one gauge can be used to counter check absolute vacuum at different places. Very help full to know that permanently mounted Dial Type Pressure gauge or U-Tube high vacuum manometer or any other gauge is giving correct reading or needs maintenance & re-calibration. A Scale is expanded from 1.0 to .001 torr and so minute reading in very last stages becomes passable.
Other vacuum measuring manometer available with us are :
U-Tube Absolute High vacuum manometer with Attached Catchpot, measure vacuum in last stages from 660 to 760 mmHg
Full range vacuum manometer, one end open to atmosphere range 0 to 760 mm Hg.
Various Ranges of Liquid Column U Tube Manometers.