TECHNICAL DATA Fluke 750P Series Pressure Modules Precision pressure measurement for 750 and 720 series calibrators The 750P Series Pressure Modules are the ideal pressure modules to enable gage, differential and absolute pressure measurement with Fluke 750 and 740 series DPCs and 725, 726 MPCs to measure pressure. Up to 0.01 % reference uncertainty 6-month and 1-year specifications Temperature compensated 0 C to 50 C Digital communication to calibrators, no analog losses or errors Broad selection of ranges Gage, differential, dual range, absolute and vacuum measurement models Eight (8) Intrinsically Safe models that are certified to: - NEC-500: Class I Div 1, Groups A-D, Ga - ATEX: II 1 G Ex ia IIC T4 Ga - IECEx: Ex ia IIC T4 Ga * All certifications: Ta = -10 C to +50 C A complete family of pressure modules A family of 50 pressure modules covers pressure calibrations from 0 to 1 in H 0 to 10000 psi (2.5 mbar to 690 bar). 2 Gage pressure modules have one pressure fitting and measure the pressure with respect to atmospheric pressure. Differential pressure modules have two pressure fittings and measure the difference between the applied pressure on the high fitting versus the low fitting. Each module is clearly labeled for pressure range and media compatibility. All modules include NPT, metric (BSP) and M20 adapters.This innovative technique provides several Quick and easy measurements benefits: Fluke 750P Series Pressure Modules are easy 1. D igital communication eliminates errors due to to use. To measure pressure, connect the pres- poor connections and electrical interference. sure module to a pressure source or hand pump 2. The modules are inherently temperature- and then connect the pressure module cable to compensated from 0 C to 50 C (32 F to 122 F). the calibrator. Apply pressure from the pressure 3. The modules are fully interchangeable because source and it is displayed digitally on the calibra- all measurements are completed in the pres- tor. At the touch of a button, the pressure may sure module itself and then communicated to the be displayed in up to 11 different engineering calibrator in digitized form. Modules are cali- units. When used with the 750 Series Document- brated independently of the calibrator, and can be ing Process Calibrators, pressure readings can be used with any 740, 750 or compatible 720 or 710 date/time stamped and stored electronically for series calibrator. Each module has its own serial later retrieval. This saves time, eliminates errors, number to maintain independent traceability. and supports compliance with quality standards and regulations. Sensor protection in isolated modules Pressure module performance Many of these modules (see table) incorporate a and technology stainless steel diaphragm to isolate the sensor. With these modules, any medium that is compatible with Fluke 750P Series pressure modules are highly stainless steel can be used on the high side of the accurate, with specifications that apply from module. 0C to 50 C (32 F to 122 F), a feature that sets them apart from other pressure calibrators. Many Rugged construction ranges have total uncertainties of 0.04 % of full scale and reference uncertainties of 0.01 % of full A urethane overmolding protects against shock if scale (see specification table). a module is accidentally dropped and also seals against dirt, dust, and moisture. Pressure connec- This performance is possible through the tions are NPT female connection. A NPT innovative application of mathematics and micro- Male, BSP/ISO and M20 male adapter are also processor power. Fluke pressure modules have provided with each pressure module. silicon piezo-resistor sensors which consist of a resistive bridge fabricated in a silicon diaphragm. Convenient setup Pressure applied to the diaphragm causes a A one-meter cable between the pressure module change in the balance of the bridge which is and calibrator reduces the length of connecting proportional to the applied pressure. The bridge tubing to the pressure source. The remote pressure balance change is not linear and is very sensi- head also provides an extra margin of safety and tive to temperature. However, since these effects convenience by removing the calibrator and are quite stable with time and with repetitive operator from the pressure source in the event or changes of condition, the sensors are carefully need for semi-remote measurements. characterized. During manufacture, Fluke pressure module sen- sors are characterized by reading temperature and pressure at multiple points. A least-squares regression is used to calculate the coefficients of a polynomial expression for pressure. The coeffi- cients, unique to that pressure module, are stored in the modules memory. Each module has its own microprocessor, allowing it to run the measurement circuitry and to commu- nicate digitally with a calibrator. When connected to the calibrator, the modules coefficients are uploaded from the pressure module to the calibra- tor. Then, as pressure measurements are made, raw sensor values for pressure and temperature are digitally loaded to the calibrator, where the raw sensor values and coefficients are manipulated to derive and display the pressure reading. 2 Fluke Corporation Fluke 750P Series Pressure Modules