--- title: "Parker Velcon FDPM Fluid & Fuel Quality | Aethair" description: "Parker Velcon FDPM flow differential pressure modules in the Aethair sensor catalog: 2 models for aviation-fuel filter condition per ATA 103, via Thiamis." url: https://aethair.io/sensors/parker-velcon-fluid-fuel-quality/ --- Sensors · Fluid & Fuel Quality # Parker Velcon FDPM Fluid & Fuel Quality The Parker Velcon FDPM (Flow Differential Pressure Module) is used on aviation-fuel filter vessels. It continuously measures flow rate and differential pressure and computes flow-corrected differential pressure per ATA 103 / JIG to indicate filter/coalescer condition. [Schedule a call](https://calendly.com/d/ctdd-mkr-v9v/aethair-demo-website) [Build a Configuration](https://aethair.io/build/?params=flow,differential_pressure_fluid) At a glance **2** parameters **2** models [**Connects via Thiamis** RS-232 · ASCII](https://aethair.io/products/thiamis/) Measures ## What the Parker Velcon FDPM Measures 2 parameters, each linked to its page: the sensors, units, and standards behind it. [Flow Rate US gpm](https://aethair.io/parameters/flow/) [Fluid Differential Pressure psi](https://aethair.io/parameters/differential_pressure_fluid/) [Connects via **Thiamis**](https://aethair.io/products/thiamis/) Wired interface [RS-232 ASCII](https://aethair.io/products/thiamis/#port-rs232) Models ## Parker Velcon FDPM Models 2 models, each with what it measures and the ranges its datasheet gives. | Model | Description | Measures & specs | | - | - | - | | **FDPM MK II** | Current Flow Differential Pressure Module; measures fuel flow rate and vessel differential pressure and auto-computes flow-corrected DP per ATA 103 / JIG. Adds an interactive, glove-friendly touch screen and condition-based alarms that can halt fueling; suits mobile or stationary equipment. | [Flow Rate](https://aethair.io/parameters/flow/) [Fluid Differential Pressure](https://aethair.io/parameters/differential_pressure_fluid/) | | **FDPM** | Original field-tested Flow Differential Pressure Module; same flow + differential-pressure sensing and flow-corrected DP calculation. Superseded by the FDPM MK II. | [Flow Rate](https://aethair.io/parameters/flow/) [Fluid Differential Pressure](https://aethair.io/parameters/differential_pressure_fluid/) | Standards ## Standards for What It Measures Standards that set limits on the parameters it reports, plus any method standard the instrument is built to. Built to [ATA 103 / EI 1581: aviation fuel filtration and differential pressure](https://aethair.io/standards/ata_103/) Solutions ## Where the Parker Velcon FDPM Is Used Solutions whose recommended configuration uses this instrument or whose standards it is built to, followed by solutions whose core panel it partly measures. ### [Hydraulic & Fuel Cleanliness](https://aethair.io/solutions/industrial-fluids/) ISO 4406 oil cleanliness and aviation fuel On the platform ## What the Parker Velcon FDPM Gets From Aethair Connected through Thiamis, its readings arrive in the same Environet account as Aethair's own monitors. ### [Live data and alerts](https://aethair.io/platform/environet/) [Environet](https://aethair.io/platform/environet/) shows the instrument live and alerts the people you choose by email, SMS, and webhook, at the thresholds you set. [Noesis](https://aethair.io/platform/noesis/) sets up a dashboard, a report, or an alert from a plain-text request. ### [Compliance reports](https://aethair.io/platform/reports/) [Aethair Reports](https://aethair.io/platform/reports/) produces scheduled or on-demand reports from the instrument's readings, as a PDF or secure link. Templates cover Aethair Blue, WELL v2, cabin air (ISO 23875), and the CMS-2567 healthcare codebook (ASHRAE 170), or you can report against custom limits such as OSHA PELs, NAAQS, EPA guidance, or your own program limits. ### [Dashboards and the app](https://aethair.io/platform/dashboards/) Environet dashboards and the [Aethair App](https://aethair.io/platform/app/) show the instrument's readings just like any Aethair device. The occupant-facing [Aethair Dashboards](https://aethair.io/platform/dashboards/) status display is built around Aethair IAQ and Aethair PRO. Similar ## Other Fluid & Fuel Quality ### [Parker](https://aethair.io/sensors/parker-fluid-fuel-quality/) [Fluid & Fuel Quality](https://aethair.io/sensors/parker-fluid-fuel-quality/) [Parker icountPD inline/online laser particle detector for hydraulic, lube-oil, and fuel systems;…](https://aethair.io/sensors/parker-fluid-fuel-quality/) Questions ## Parker Velcon FDPM FAQ What does the FDPM measure, and how does it indicate filter condition? It continuously reads the fuel flow rate and the differential pressure across a filter or filter/separator vessel, then computes the flow-corrected differential pressure. Because raw differential pressure rises with flow, ATA 103 and JIG require it to be normalized to a reference flow before it can indicate element loading. The FDPM does this automatically and warns as the corrected value approaches the change-out limit. What is flow-corrected differential pressure? Differential pressure across a filter changes with flow rate, so a raw reading cannot be compared against a single fixed limit. Corrected differential pressure scales the measured value to a standard flow (per ATA 103 / JIG), giving a flow-independent number that reflects true filter condition. On Aethair, both the raw and corrected values map to the Fluid Differential Pressure parameter, which is kept separate from room differential pressure measured in air. How does the Thiamis integration read the FDPM? Over an RS-232 ASCII stream at 9600 baud, 8-N-1. The logger sends START and the module streams comma-separated records carrying a timestamp, a unit id, and the measured flow, differential-pressure, and corrected-DP values; the driver averages each field over the reporting interval before posting flow (US gpm) and differential pressure (psi). How does the FDPM MK II differ from the original FDPM? The MK II is the current unit and keeps the same flow and differential-pressure sensing and ATA 103 / JIG corrected-DP calculation. It adds a glove-friendly touch-screen display and condition-based alarms that can be set to halt fueling, and suits both mobile and stationary equipment. The original FDPM is its field-tested predecessor. Where is the FDPM used? On aviation-fuel filter, filter/separator, and filter-monitor vessels (on refueler trucks, hydrant dispensers, and fixed installations), to monitor coalescer and filter-element condition during fueling and support ATA 103 record-keeping. Sources: [www.parker.com](https://www.parker.com/content/dam/Parker-com/Literature/Aerospace-Filtration/VEL2166-CAT-Fuel-Condition-Monitoring-Control-Sensors.pdf) · [www.aviationpros.com](https://www.aviationpros.com/ground-support-worldwide/gse/fueling-equipment-accessories/fuel-handling-monitoring-systems/product/10133597/parker-velcon-fdpm-flow-differential-pressure-module)