Do you have all necessary hardware to connect components together and to the device under test? After you have all the main components of your system identified, you will need to make sure you are able to connect it all together.
Connect from your pressure supply to generation and control hardware: This may include regulators, filters, gauges, fittings and tubing from a test gas bottle (or a reservoir of fluid for hydraulic applications) to your pressure controller. It may also include valves, filters, fittings and lines from sources of shop air or vacuum supply. Fluke Calibration offers high pressure flexible tubing and other hardware to plumb supply pressure to the controller. Verify that all of the hardware is rated by the manufacturer to operate at the intended pressure ranges. It is recommended to implement relief valves or rupture disk into the system to protect the equipment and operators from overpressurization.
Connect the components of the system together: If you plan to use separate measurement and control hardware, or if there are other components required to make the measurement (i.e. a vacuum pump for absolute mode or multiple reference devices), do you have all the necessary hardware to connect these devices together? Note that in some cases, you may need to isolate and/or vent one or more of the components, or to bypass high and low test lines, so you may need an external pressure valve(s). Fluke Calibration offers interconnect kits for our pressure products, to combine the various components into a calibration system.
Pressure line from the reference system to the device under test: The test pressure line should not be too restrictive (i.e. small diameter), yet should not be too voluminous. Either condition may lead to operational and/or measurement error by inducing a differential pressure or causing undesirable transient conditions. All pressure lines and fittings should also be scrutinized to make sure they are safe for the application. Consult a Fluke Calibration product application specialist if you are unsure of which type of pressure line is most appropriate for your application. Verify the minimum or maximum control volume of the standard that you are using.
Protect the system from contamination: Often gauges, switches, transducers, transmitters and calibrators are contaminated in process or from other devices. Precautions should be taken to prevent contamination in the DUTs from getting into the calibration standard, where it can cause errors and costly damage. DUTs may need to be cleaned before calibration. Even after cleaning, filtering may be needed between the DUT and the reference standard. Fluke Calibration offers liquid traps for effective filtering without introducing excessive restrictions in the test line. We also offer fluid separators and differential pressure cells, for when contamination is excessive, or the DUT medium is different from the reference medium. A potential source of contamination can be from the vacuum supply. When a fluid filled vacuum pump is turned off, fluid from the vacuum pump can be drawn into the standard. It is often recommended to fit the fluid filled vacuum pump with auto vent solenoid valves to vent the vacuum when power is lost to the vacuum pump.
Connect the device under test (DUT) to the test port: Special consideration should be given to the pressure connection from the reference port to the device being tested. The DUT is changed frequently, so it requires a connection that is conveniently made and broken, yet does not easily wear. Fitting wear can lead to debris in the test line, and to leaks that can be problematic for operation or result in faulty pressure measurements.
Do you have the means to mount and apply pressure to the device under test (DUT)? You have spent a lot of time identifying the right calibration equipment – Make sure you are able to effectively use it with the DUTs. Do you require a gauge stand or test manifold to safely mount the DUT? Take note that some DUTs must be mounted in a particular orientation for proper performance. Is a custom-bent or flexible test line needed to adapt to different styles of DUTs? Will you need special fittings or adaptors to be able to connect from the DUT test port to that of the system?
How are you going to read and record the device under test readings? Are you calibrating a dial gauge or digital indicator? Does the device being tested feature remote communications so you can collect data with software? If you are calibrating pressure transducers, pressure transmitters or pressure switches, do you have a power supply and means to read the device under test (i.e. DMM)? How are you going to record the results – Can data logging be automated (COMPASS for Pressure software reads, averages, and stores the reading of the test device or DMM and the reference device) or semi-automated (COMPASS for Pressure software records the reference device and a cardinal value for the test device, or prompts the user for the reading). See "To what extent can the calibration process be automated?" to learn more about the benefits of automating and automation options.
Do you have all the mounting and transportation hardware needed? Is the equipment to be mounted in a rack? Do you need to regularly send the equipment for service (such as annual calibration) or transport from one location to another? Fluke Calibration offers rack-mount hardware, transportation/storage cases, replacement batteries and other accessories that may be needed.
Do you have all the required consumables and preventative maintenance hardware? Whether calibrating with a hydraulic or gas medium, be sure to have an adequate supply of test medium. Fluke Calibration offers some consumable fluids, or you can work with your local vendor. For gas calibrations, make sure you have an adequate source of clean, dry gas onsite, or arrange delivery of compressed gas cylinders with your local supplier. You may also want to have a supply of o-rings, filters and other wear parts to keep your system up and running.
Do you have a plan to maintain your equipment? Calibration reference standards require regular calibration themselves, ranging from a frequency of once every several months to several years, depending on the type of equipment and the conditions in which they are used. Make sure you will be able to support these calibrations, or identify a laboratory that has the capability to do so. Fluke Calibration pressure products are designed to be calibrated by any laboratory with adequate capabilities (calibration coefficients are accessible and can be edited). We also offer world class calibration services, including onsite services, for Fluke-branded and most other pressure devices. Fluke products are repaired in our service labs and authorized service providers worldwide. You can protect and support your investment up front with a Fluke Calibration CarePlan, which provides an extended warranty and other service benefits. Some plans also include annual calibration.
Will you benefit from training? The science of pressure metrology, or design and implementation of effective pressure calibration solutions are challenging subjects, even for the most experienced engineer or technician. Fluke calibration offers training courses appropriate for every level, ranging from the fundamentals of pressure calibration, to automation of the pressure calibration process, to advanced pressure metrology and crossfloating. We can even customize courses and individual training for your specific needs. Fluke Calibration also offers installation services to start up a new system or to improve an existing pressure calibration process.