The Drop Bar Gauge Assembly was made to carry two Electronic Memory Recorders inside an enclosure that will be dropped into a Well to fire the Tubing Conveyed Perforating Guns (TCP drop bar firing head). The basis of design was to ensure that most of the impact was absorbed by shock absorbers, protecting the electronic gauges from the full shock of impact with the firing head and the re-coil impact from the guns detonating.

The drop bar assembly has a series of shock absorbers – one hydraulic and three springs. At impact the hydraulic shock absorber takes the initial compression, similar to a car shock absorber, after the hydraulic shock absorber has compressed approximately 30% the first spring shock absorber starts to compress, once the hydraulic and spring shock absorber are fully compressed a 2^nd and 3^rd spring absorbs any remaining shock. 

In addition to the hydraulic and spring shock absorbers we have also installed 9 Rubber Finger Centralizers that keep the Drop Bar Assembly centered in the tubing and reduces the velocity of the Bar Assembly through the fingers rubbing against the tubing causing enough friction to reduce the over-all speed at which the bar drops and in turn reducing the severity of the impact on the firing head.

The combination of hydraulic and spring shock absorbers reduces or eliminates any severe vibration or shock on the Gauge electronics to ensure that good quality pressure and temperature data is collected while the Drop Bar Assembly is traveling inside the tubing, just prior to impact, immediately upon impact and after impact.