YD9810 shaft vibration transmitter

YD9810 linearizes and normalizes shaft-vibration displacement peak-to-peak measurement into a 4–20 mA signal for a DCS or PLC. A buffered output exposes the original eddy-current signal.

Parameter	Stated value
Resolution	0.05%
Temperature drift entry	≤0.05/°C; missing percentage unit unresolved
Operating temperature	−25 to +70 °C
Supply	+24 V DC
Current output	4–20 mA
Buffered output	Original eddy-current signal
Maximum load	750 Ω
Frequency response	4.0 Hz–4 kHz
External probe in specification	8 mm eddy-current probe
Protection	IP44

Standard calibration uses a 40CrMo steel specimen unless another material was specified. Confirm that the monitored shaft has the same or similar eddy-current response; for higher accuracy, the manual calls for calibration against the actual target. Surface residual magnetism, nonuniform hardening and material structure can affect response. The manual cites an API 670 recommendation of no more than 0.5 µT residual magnetism; this is the source's statement rather than an independently checked standard requirement.

For radial shaft vibration, use two probes in one plane separated by 90° ±5°. The usual arrangement is 45° to each side of the vertical centerline. Viewed from the driver end, the source identifies X on the right and Y on the left. Locate probes near the bearing, but resolve the document's 152/76 mm distance conflict for the actual installation.

The probe axis should intersect the shaft axis at right angles. The monitored circumferential track must be free of scratches, oil holes, keyways, plating and other discontinuities. The stated surface roughness is 0.4–0.8 µm. The manual specifies a shaft diameter greater than 40 mm for radial measurement. Confirm the track width and mechanical clearances with the installation drawing.

Normally the radial-vibration probe is set near the middle of its calibrated linear range. Use the actual calibration sheet or curve to obtain both the gap and the corresponding voltage; the conflicting general voltage examples in this source are not substitutes for that data. For a large horizontal machine, the source notes about 0.25 mm shaft lift at startup and describes a cold vertical-probe gap about 0.25 mm larger than the midpoint, when applicable to the machine.

The plastic probe head must project completely beyond the metal mounting face. Otherwise a suitable counterbore or chamfer is required. Probe spacing must prevent mutual interference and depends on probe size and orientation. The bracket should be rigid, with its resonant frequency at least ten times rotational frequency.

During insertion, surrounding metal can produce an apparently correct output before the probe actually sees the shaft. The described output sequence is: high saturation outside the hole, lower output inside the hole, high output again when the head emerges but remains far from the target, and then the required gap output as the probe approaches the target. Confirm the head is exposed and the final reading belongs to the shaft.

Do not force the probe against the target. Rotate its cable with the probe; disconnect any extension cable before turning the probe to prevent twisting damage.

Probe connectors are electrically connected to the internal circuit and are not sealed. Cover joined connectors with heat-shrink tubing to insulate them from the machine, improve sealing and resist loosening. The manual advises against adhesive electrical tape because oil mist can dissolve adhesive and contaminate the connection. Do not shorten or extend a selected probe/extension cable arbitrarily; doing so changes the sensor system.

Install the transmitter in a dry, low-vibration location without corrosive gas and preferably near room temperature. Use a dedicated enclosure for installation beside the machine. The source calls for single-point grounding. Its transmitter case is internally connected to the signal reference, and insulating mounting parts are intended to isolate the case from earth.

Use braided-shield output cable. Connect its shield to signal ground at the DCS end only, leaving the transmitter end unconnected. The original-signal output cable must not exceed 300 m according to this source. Obtain the approved terminal drawing for the supplied unit before wiring.

The probe head is PPS and the housing is 1Cr18Ni9Ti stainless steel. The source prohibits prolonged exposure to anhydrous ammonia, benzaldehyde, nitric acid, chloroform, potassium permanganate and 98% sulfuric acid. Confirm chemical suitability for the actual environment.

Recalibration is called for after more than one year out of use, after two years of continuous service, when the target differs from the factory calibration material, and after a fault has been corrected.

The equipment list includes a displacement calibrator, micrometer, digital multimeter, +24 V DC supply and sine-wave generator; the output procedure also requires a vibration table. Use a specimen matching the target material and a micrometer span more than 20% greater than the sensor range. Connect the probe, supply and meter, establish the reference against the specimen, and move to the calibrated linear starting distance.

For the transmitter-output check:

1. Set the stationary probe at the linear midpoint; OUT should be 4.00 mA ±1% as stated.
2. On a vibration table, apply the appropriate frequency and a midscale vibration amplitude; OUT should be 12 mA ±1%.
3. Apply the appropriate frequency and full-scale vibration amplitude; OUT should be 20 mA ±1%.
4. If these checks fail, the documented remedy is factory calibration.

A static midpoint gap and a midscale vibration amplitude are different conditions. The source does not specify the vibration frequencies or amplitude numbers for every ordered range.

Start with terminal assignment, open/short circuits, supply voltage and the connected measurement instrument. Then check the probe and extension cable before condemning the transmitter.

Clean a dirty probe face or high-frequency connector with anhydrous alcohol as instructed. Check the extension cable for open or short circuits and replace it if faulty. Disconnect the extension and measure resistance between the probe connector pin and shell: the source gives 2.0–10.0 Ω as normal, less than 1.0 Ω as shorted, and greater than 10 Ω as open or a poor contact. Replace a probe identified as faulty. The manual does not classify the interval from 1.0 to below 2.0 Ω.

For a transmitter check, first verify that the probe, extension and transmitter are a matched set and connect the required extension. With a known-good probe, the buffered original signal should be smallest near a conductive target and largest far from it. Failure to show this response indicates a transmitter fault or poor system connection in the source procedure; repair the connection or replace/service the transmitter as appropriate.

The source uses YD9810-A-B-C-D-E-F-G-H-I. A includes 5 mm standard/imperial/reverse-mount variants (51–54) and 8 mm variants (81–83 shown). This differs from the technical table's single 8 mm specification and requires configuration confirmation.

B01/B02/B03 select 0–100/200/300 µm peak-to-peak. C01 is regular response and C02 low-frequency response; cutoff values are not given here. D01–D06 are M8 × 1, M10 × 1, M14 × 1.5, 1/4–28, 3/8–24 and 1/2–20. E is unthreaded length, with entries from 00 = 0 mm through 10 = 10 mm. F is body length, with 20 = 20 mm, 50 = 50 mm and 250 = 250 mm shown.

G is extension cable: 00 = none, 40 = 4 m, 50 = 5 m, 80 = 8 m, 85 = 8.5 m and 90 = 9 m. H is total cable length, with 4, 5, 8 and 8.5 m examples. I00 is armored and I01 unarmored. Cable fields must be resolved as a matched system; they are not permission to alter the cable after calibration.