The Model 2468 Pitot Static Primary Standard is specifically designed for calibrating today’s high performance flight line and Air Data Test Systems. With the new autofloat controller, operator intervention is reduced to simply applying the mass load indicated by WinPrompt® software. WinPrompt applies all required correction factors, real time, to insure attainment of the highest level of performance available in a gas piston gauge which is required to calibrate today’s RVSM compliant test sets. The Model 2468 is based on the popular Model 2465 Gas Piston Gauge which has a long history of serving national standards laboratories, commercial industry and government organizations as a primary pressure standard for over 50 years. Time-proven materials, hand craftsmanship, and a lineage of intercomparisons to national standards laboratories at the highest levels are coupled with new automated technology to make the Model 2468 Pitot Static Primary Standard the world’s choice for calibrating Air Data Test Systems.

Piston/cylinder assemblies

For calibrating most Pitot Static Test Sets, only the standard piston/cylinder supplied is required. The standard piston/cylinder generates pressures from 1.4 to 103 inHg in autofloat mode and from 0.4 to 103 inHg using a manual pressure adjuster. This provides an effective altitude range from -610 to 19,812 meters (-2,000 to 65,000 feet) feet in autofloat mode -610 to 27,432 meters (-2,000 to 90,000 feet) using a manual adjuster) and airspeeds over 1,000 knots. An optional piston/cylinder is available for generating pressures from 3.4 to 400 inHg allowing calibration of other pressure related devices, such as pressure transducers.

Both the standard and optional piston/ cylinder assemblies are manufactured from proven materials that have evidenced superior strength, durability, low distortion, low thermal coefficients and virtually undetectable hysteresis over the last several decades, and have an unparalleled record of long-term stability. Each piston/cylinder installs quickly into the pressure column without the need for special tools. Piston/cylinder assembly change-out can be completed in less than one minute.

Mass set

The Model 2468 is provided with a single mass set that is used with either the standard or optional piston/cylinder. Each mass is engraved with a unique sequence number and a common serial number. A storage case is supplied which allows storage of the mass set and one or both piston/cylinders. Each mass is machined to a nominal value and is made from nonmagnetic materials to provide long-term stability and eliminate sensitivity to magnetic fields. For ease of use, the entire mass set totals just 12 kilograms (26.40 pounds), with a maximum platter mass of 1 kilogram (2.2 pounds). A laboratory grade trim mass set is included to allow any pressure increment within the range and resolution of the piston/cylinder assembly.

Instrument base

The instrument base is designed with functionality, economy and space conservation in mind. All electronic components are housed away from the instrument base to eliminate errors caused by thermal effects and magnetic fields. The thermally isolated motor drive is connected to the cylinder—eliminating pressure fluctuations and maximizing productivity. A durable, acrylic bell jar is provided to allow absolute mode operation when calibrating altitude and other absolute reference devices. A KF16 fitting is provided to simplify installation and allow low reference pressures

Vacuum pumps

In order to operate over the entire altitude and airspeed range, two vacuum pumps are required. One pump is connected to the reference port of the Model 2468 using a KF16 connection. This allows the area inside the bell jar to be evacuated which is required for altitude calibrations (absolute mode). A second vacuum pump is connected to the autofloat controller which allows automatic control of pressures down to 1.4 inHg absolute. In order to generate positive pressures, a regulated gas supply (clean dry air, or nitrogen) must be supplied to the autofloat controller. Fluke Calibration can supply vacuum pumps which are rated to the appropriate vacuum capacity and include an auto-vent valve and backstream filter for contamination prevention along with a muffler for quiet operation.

Connecting lines and fittings

Fluke Calibration can provide an optional lines and fittings kit which includes all interconnecting tubing for pressure and vacuum supplies along with all required cables and adapters.

Manual configuration

Fluke Calibration also offers a manually operated pressure control system for setting the pressure and float position. This configuration can also be used with WinPrompt software and the Model 2456 Deadweight Gauge Monitor. The Model 2456 continuously monitors piston temperature, float position, and sink rate, and optionally air density and reference vacuum. WinPrompt calculates mass-to-pressure and pressure-to-mass values, and when used with the Model 2456, automatically reads and displays real-time piston gauge parameters. A separate brochure is available that covers the Model 2456 Deadweight Gauge Monitor.