Hydac HDA 4844-A-400-000 High-Accuracy Pressure Transmitter

Test-rig accuracy in a standard pressure-port body

The Hydac HDA 4844-A-400-000 (HYDAC part number 922671) is the high-accuracy line of the HDA 4800 series. The typical accuracy is 0.125 % of full scale to DIN 16086, half the figure of the HDA 4700, and the temperature effect is also halved. That is why HYDAC describes it as particularly suited to test benches and diagnostic work, while it still serves general industrial use.

This order code covers 0 to 400 bar, 4 to 20 mA on two conductors, a G1/4 A male port and a four-pole Binder series 714 M18 plug whose mating connector is not supplied.

Technical specifications

When to specify the HDA 4800

Choose it when the measured value feeds calibration, a test report or a closed-loop controller and an error of 1 bar at 400 bar (0.25 %) matters. Compared with the HDA 4700 the extra accuracy comes at a higher price, so for ordinary monitoring the 4700 is the more economical selection. The low temperature coefficient helps where the fluid temperature changes during a test cycle.

Order code and connector

HDA 4 8 4 4 – A – 400 – 000: the first 4 is the G1/4 A port, the second 4 the Binder 714 M18 four-pole plug, A the 4 to 20 mA signal, 400 the bar range. Other digit combinations select the EN175301-803 plug or M12x1, and a B signal gives 0 to 10 V on three conductors. Buy the matching Binder socket separately as an accessory. The datasheet (E 18.380.1) is the USA edition printing psi ranges (150 to 9000 psi) and SAE-6; the metric 400 bar item is listed in the HYDAC catalogue with the same electrical data.

Keep the signal cable shielded and fit the Binder socket correctly, because the best accuracy depends on a stable supply and a good ground. Allow the transmitter to reach the fluid temperature before taking calibration readings.

Specify the Binder socket and cable length with the transmitter when you order, and plan for a documented calibration check if you will use the readings as a reference. Supply the exact full code so the right range and connector are quoted, because the same body number covers several other ranges and signal options.

Documents and quotation

The HDA 4800 datasheet is attached. Please send the full code and quantity. See also our pressure instrumentation range.

How the HDA 4844-A-400-000 measures pressure

The HDA 4800 series uses a very accurate and robust sensor cell: a thin-film strain gauge deposited on a stainless steel membrane. System pressure deflects the membrane by a tiny amount, the strain gauge bridge converts that deflection into a change of resistance, and the integrated amplifier turns it into a 4 to 20 mA loop current that is proportional to pressure. Because the measuring element is a thin-film cell and not a piezoresistive chip behind an oil fill, the cell stays stable over a wide temperature span. HYDAC states a life expectancy of more than 10 million load cycles from 0 to 100 % FS and a rise time of 1 ms.

The two-conductor 4 to 20 mA signal of the HDA 4844-A-400-000 is easy to work with: supply and signal share the same pair, a broken wire shows up as a current below 4 mA, and the live zero lets the controller tell a real zero pressure from a fault. Reverse-polarity, over-voltage, override and short-circuit protection are provided in the electronics.

Additional performance data

Selection & ordering guide

Pick the measuring range so that the normal operating pressure sits in the upper half of the scale, while the pressure peaks remain below the overload limit. For a circuit that works at 250 to 350 bar with short peaks, the 400 bar range of the HDA 4844-A-400-000 is a sensible choice. The ordering code is read digit by digit:

• HDA 48 – HDA 4800 high-accuracy series.
• 4 – mechanical connection G1/4 A male.
• 4 – Binder series 714 M18 four-pole male plug. Other electrical options in the family include the EN 175301-803 (DIN 43650) plug and M12×1 four-pole.
• A – 4 to 20 mA, two-conductor. Option B is 0 to 10 V, three-conductor.
• 400 – measuring range in bar.
• 000 – standard modification.

If a replacement must match an existing sensor exactly, read the full code from the label of the old unit. A different connector digit changes the mating plug, and a different signal letter changes the wiring, even though the body looks the same.

Installation & maintenance

• Fit the G1/4 A port with its profile seal and tighten to 20 N·m. Mount the transmitter where it is not exposed to direct pressure surges from a valve; a short distance or a snubber helps on circuits with sharp switching.
• For a 4 to 20 mA loop, check the load resistance: RL max = (UB − 10 V) / 20 mA. At a 24 V supply this is 700 Ω for the controller input and the cable together.
• Use shielded cable and connect the shield at one end only to avoid ground loops, especially on test benches with frequency-controlled drives.
• For test-rig work, compare the reading against a reference gauge at regular intervals. The drift figure lets you plan a sensible calibration interval.
• Do not attempt to open or adjust the transmitter. The cell and electronics are sealed and factory-set.

Typical applications in Oman & the GCC

HYDAC positions the HDA 4800 for test rigs and diagnostic technology, and also for a broad range of industrial applications. In the region this includes hydraulic test benches in workshops and service centres, press and injection-moulding machines, steel and aluminium plants, hydraulic power units on offshore and port equipment, and water and desalination systems that need an accurate pressure reference. The low temperature coefficient is useful where machinery operates through large daily temperature swings.

Why source from Seven Star LLC

Seven Star LLC supplies HYDAC pressure transmitters across Oman and the GCC. Send us the full code HDA 4844-A-400-000 and the quantity, together with the mating Binder connector if you need it, and request a quote. Our team can help confirm the correct ordering code for a different range, signal or plug.