Inside the iTank: Ballistic Data Integrity Without the Throughput Penalty

Anyone who characterizes airbag inflators knows the method is deceptively simple and unforgiving in the details. Fire the inflator into a sealed vessel of known volume, capture the pressure-time curve, and derive the metrics that decide whether a unit passes: peak tank pressure, rate of pressure rise, and time to peak. Every one of those numbers is only as trustworthy as the tank it was measured in. Volume uncertainty, thermal drift between shots, and inconsistent sealing all propagate straight into your results — and in lot-acceptance or qualification testing, that is the difference between a defensible pass and a costly false reject.

The Microsys iTank is built around that reality. It is engineered to protect the integrity of the measurement while removing the practical bottlenecks that slow a test cell down.

iTank System on it's mobile fixture

A vessel you can trust the numbers from

The iTank is an ASME-certified pressure vessel rated to 200 PSI and hydrostatically tested to 130% of that rating, with body and door fabricated from 304 stainless steel. That construction is more than a safety statement for an energetic, pyrotechnic device — it is what keeps the internal volume dimensionally stable, shot after shot.

Because inflator output is calculated from a pressure rise inside a fixed volume, volume error maps directly onto output error. The iTank holds a volume accuracy of ±1.5%, tightening the confidence band on every derived value. A polished interior keeps combustion residue from building up and makes between-test cleaning fast, so particulate accumulation doesn't quietly bias later firings.

For instrumentation, four pressure ports come standard (NPT, with metric available), and pressure transducers are offered as an option — so the tank drops into your existing DAQ, or integrates directly with the Microsys SureFire Inflator Test System for synchronized firing, acquisition, and analysis.

Cycle time is a data-quality problem, too

Thermal management is where many tank setups quietly lose both time and accuracy. Each firing deposits heat into the vessel, and because tank pressure is temperature-dependent, a tank that hasn't returned to a stable ambient baseline will skew the next pressure-time curve. The usual remedy — waiting — kills throughput.

The iTank addresses this directly with a 14-gauge 304 stainless water-dimple cooling jacket (½" FNPT connections) that brings the vessel back to ambient quickly and repeatably. You recover your thermal baseline faster, which means more shots per shift and more consistent shots at the same time.

The mechanical design follows the same logic. A submarine-style door latch opens and closes by hand — no power tools — for fast load and unload between firings, while carbon-steel locking dogs and hinge hardware carry the pressure load. A specimen mount on the cover positions the unit under test consistently, and an optional mobile stand rotates the tank from -90° to +90° for ergonomic access and orientation-specific testing.

Sized to your program

Inflator formats vary, and so does the iTank. The 28.3-litre and 60-litre vessels cover the most common driver, passenger, and side applications, with a dedicated 60-litre curtain configuration for longer modules. The full range spans from 10 litres up to 146 and 150 litres, with custom volumes available when a program demands it — all built to the same construction and accuracy standard.

The result is a test tank that refuses the usual trade-off. You get measurement integrity you can put in a report and defend, and a cycle time your production or validation schedule can actually live with.

To spec an iTank for your application — or to pair it with the SureFire Inflator Test System — contact the Microsys team.