Technical Specifications
| Product Price | 3500 INR / Piece |
| Measuring Ranges | Eight selectable ranges depending on model, typically from ±25 Pa up to ±7000 Pa |
| Output Signals | 0–10 V, 2–10 V, or 4–20 mA (three-wire system) |
| Selectable Units | Pa, kPa, mbar, inch WC, mm WC, psi |
| Accuracy | For pressures below 125 Pa: ±(1% + 2 Pa) | For pressures above 125 Pa: ±(1% + 1 Pa) |
| Zero Calibration | Automatic or manual zero (depending on model version) |
| Response Time | Adjustable between 0.8 s and 8 s |
| Over-pressure Protection | Proof pressure up to 25 kPa, burst pressure up to 30 kPa |
| Media | Dry air or non-aggressive gases |
| Temperature Range | Operating −20 °C to +50 °C |
| Display | Optional LCD back-lit display (for D versions) showing measured value and unit |
| Power Supply | 24 VAC / DC |
| Protection Class | IP54 |
| Housing Material | ABS base with polycarbonate cover |
| Connection Ports | 5 mm and 6.3 mm pressure fittings |
| Weight | Approximately 150 g |
DPT-R8 Differential Pressure Transmitter
The DPT-R8 is Agile Nobel’s air differential pressure transmitter, built to measure the pressure difference between two points in an air or gas system and convert that reading into a continuous, calibrated output signal. It covers eight selectable ranges from ±25 Pa up to ±7000 Pa, with a choice of 4–20 mA, 0–10 V or 2–10 V output, so one differential pressure transmitter can be specified across most low-pressure air monitoring points in a building or industrial process instead of stocking a separate fixed-range unit for every application.
As a purpose-built HVAC pressure transmitter, the DPT-R8 is designed around the way air-handling systems actually fail: gradually, as filters load with particulate and fan performance drifts, rather than suddenly. Because it outputs a continuous analog signal instead of a single on/off trip point, a building management system can track that drift over time and flag maintenance before airflow is visibly affected — in air handling units, supply and return ductwork, cleanrooms, pharmaceutical manufacturing areas, hospitals, and laboratory pressure zones.
Not every application needs a continuous-output pressure transmitter — if you only need a simple threshold alarm, our differential pressure switch DPS-930 is the lower-cost option (see the comparison below). For other media types and pressure ranges, browse the full pressure transmitter and switch range, or read our complete differential pressure transmitter buying guide for a full walkthrough of selection criteria, application requirements, and common mistakes to avoid when specifying a transmitter.
What is a differential pressure transmitter?
A differential pressure transmitter is an instrument that measures the difference in pressure between two separate points in a system — for example, the two sides of an air filter, or the inlet and outlet of a fan — and converts that difference into a proportional electrical signal. Unlike a single-point pressure gauge, a differential pressure transmitter is specifically built to detect the kind of gradual pressure change that indicates a filter clogging, a fan losing efficiency, or a room losing its required pressure differential relative to the space next to it. That continuous signal is what makes a differential pressure transmitter suitable for automated monitoring, rather than requiring someone to manually check a gauge.
Why HVAC systems need a dedicated pressure transmitter
Air handling systems are pressure-driven: fans push air through ducts, filters, and dampers, and every one of those components is designed to operate within a specific pressure range. A dedicated HVAC pressure transmitter installed across a filter or fan gives a building management system the real-time data it needs to know whether that range is still being maintained. Without it, filter changes happen on a fixed calendar schedule whether the filter needs it or not, and a slowly failing fan can go unnoticed until airflow complaints start. With a properly specified air differential pressure transmitter in place, both of those become measurable, trackable conditions instead of guesswork.
Key features
- Eight selectable measuring ranges (±25 Pa to ±7000 Pa) — one differential pressure transmitter covers everything from low-pressure cleanroom differentials to higher-pressure industrial duct monitoring, set on the device itself rather than requiring a different model per range.
- High-accuracy measurement — ±(1% + 2 Pa) below 125 Pa and ±(1% + 1 Pa) above 125 Pa, so this pressure transmitter stays reliable at both the low and high ends of its range.
- Flexible analog output — 0–10 V, 2–10 V, or 4–20 mA (three-wire), selectable to match whatever input type your BMS or PLC already expects.
- Selectable engineering units — Pa, kPa, mbar, inch WC, mm WC or psi, configured on the transmitter without needing an external conversion step.
- Stable long-term performance with automatic or manual zero calibration (model-dependent), keeping this air differential pressure transmitter accurate without frequent recalibration visits.
- Fast, adjustable response time of 0.8–8 seconds, tunable to how quickly the monitored process actually changes.
- Built-in over-pressure protection — rated to 25 kPa proof pressure and 30 kPa burst pressure, protecting the sensing element from duct pressure spikes during startup or damper actuation.
- Compact, IP54-rated housing — ABS base with a polycarbonate cover, around 150 g, sized to mount in tight duct or panel spaces without extra bracketry.
- Minimal maintenance once commissioned — a sealed housing and no moving parts in the sensing path make this pressure transmitter suited to continuous, unattended operation for years between service visits.
Applications
HVAC & building automation — As an HVAC pressure transmitter, the DPT-R8 continuously monitors duct static pressure, supply and return fan performance, and damper position feedback across air handling units and ventilation systems, feeding live readings into the building management system instead of a periodic manual check.
Filter & fan monitoring — Mounted across a filter bank, this differential pressure transmitter tracks the pressure drop as the filter loads with particulate over weeks or months, letting maintenance teams schedule filter changes based on actual loading rather than a fixed calendar interval — reducing both premature filter replacement and the risk of running an overloaded filter too long.
Cleanrooms & pharmaceutical manufacturing — Cleanroom classifications and pharmaceutical manufacturing standards require maintaining specific pressure differentials between adjoining spaces at all times; a continuous-output pressure transmitter is what makes that differential measurable and loggable for compliance records, not just visually checked on a gauge.
Hospitals & laboratories — Isolation rooms, operating theatres, and lab fume hood zones depend on maintaining a specific pressure relationship with adjacent spaces; the DPT-R8’s continuous signal supports both real-time alarming and historical logging for these safety-critical differentials.
Industrial process control — Beyond HVAC, this differential pressure transmitter integrates into PLC-based process control loops via its 4–20 mA or 0–10 V output wherever a process depends on monitoring or controlling a low-pressure air or gas differential.
Differential pressure transmitter vs. differential pressure switch
A common question when specifying is whether an application needs a full differential pressure transmitter or a simpler differential pressure switch. A transmitter, like the DPT-R8, outputs a continuous, proportional signal across its measuring range — useful when you need to see the actual pressure value, track a trend over time, or integrate the reading into a control loop. A switch, like our DPS-930 differential pressure switch, is a simpler on/off device that trips at a single pre-set threshold — a lower-cost option when all you need is a binary alarm (e.g., “filter is clogged: yes/no”) rather than a continuous reading. If you’re unsure which fits your application, our buying guide walks through the decision in more detail.
Why choose the DPT-R8 from Agile Nobel
The DPT-R8 combines eight selectable ranges and three output types in a single unit, so one air differential pressure transmitter model covers most HVAC and light industrial pressure-monitoring needs instead of requiring a different fixed-range transmitter per application.
Frequently Asked Questions
Q1. What is a differential pressure transmitter?
Ans: A differential pressure transmitter is a device that measures the pressure difference between two points in an air, gas, or liquid system and converts that difference into a continuous analog output signal (such as 4–20 mA or 0–10 V) for monitoring or control.
Q2. How does a differential pressure transmitter work?
Ans: It uses a sensing element connected to two pressure ports. As pressure differs between the two points, the sensor deflects proportionally, and internal electronics convert that deflection into a calibrated, continuous output signal sent to a display, PLC, or building management system.
Q3. What’s the difference between a pressure transmitter and a differential pressure transmitter?
Ans: A standard pressure transmitter measures pressure at a single point relative to atmospheric or absolute pressure. A differential pressure transmitter measures the difference between two separate points—for example, across a filter or fan—which is what’s needed to detect changes like filter clogging that a single-point reading can’t show.
Q4. What’s the difference between a pressure-indicating transmitter and a standard transmitter?
Ans: A pressure-indicating transmitter includes a built-in display (like the DPT-R8’s optional backlit LCD on D-series models) so pressure can be read directly at the device, in addition to sending the analog output signal to a remote system.
Q5. Where is a differential pressure transmitter typically installed?
Ans: Common installation points include across air filters, on either side of supply and return fans, in cleanroom and lab pressure zones, and inline in ductwork wherever airflow or pressure needs continuous monitoring.
Q6. How is a differential pressure transmitter used in HVAC systems?
Ans: In HVAC, it continuously monitors duct static pressure, filter pressure drop, and fan performance, feeding readings to a building management system so filter changes and fan adjustments can be scheduled based on actual conditions rather than a fixed calendar interval.
Q7. Can the DPT-R8 be used for filter monitoring?
Ans: Yes—mounted across a filter, it tracks the pressure drop as the filter loads with particulate, and the continuous analog output lets a BMS trigger a maintenance alert at whatever pressure threshold indicates the filter needs replacement.
Q8. What output signals are available on the DPT-R8?
Ans: 0–10 V, 2–10 V, or 4–20 mA (three-wire), selectable to match the input type your building management system or PLC requires.
Q9. How do I choose the right measuring range for my air differential pressure transmitter?
Ans: Match the range to the expected pressure differential of your application with some headroom—for example, cleanroom pressure differentials are typically well under 125 Pa, while duct static pressure or fan monitoring can run into the hundreds or low thousands of Pa. The DPT-R8’s eight selectable ranges (±25 Pa to ±7000 Pa) cover both ends without needing a separate model.
Q10. Is this pressure transmitter suitable for cleanroom use?
Ans: Yes—its low-end range and ±(1% + 2 Pa) accuracy below 125 Pa make it suitable for monitoring the tight pressure differentials cleanroom classifications require between adjoining spaces.