PCB Piezotronics 640B01 4-20 mA Velocity Transmitter
Overview
The PCB Piezotronics 640B01 is a Platinum-series 4-20 mA velocity transmitter from the IMI Sensors industrial range. Instead of a raw dynamic waveform, it delivers a loop-powered current signal proportional to overall vibration velocity, scaled from 0 to 1 in/sec peak (0 to 25.4 mm/s peak). That makes it a direct way to bring machine vibration into a PLC, DCS or SCADA system as an ordinary analog input, without a separate signal conditioner or vibration monitor in the panel.
Seven Star LLC supplies the PCB Piezotronics 640B01 to automation contractors, utilities and process plants across Oman and the GCC that want continuous vibration trending and alarming on pumps, fans and motors. Our Muscat team supplies vibration transmitters on request and can help with the full loop: sensor, mounting stud, cable, junction box and the PLC scaling and alarm set points that follow general vibration severity practice.
Operating Principle
The PCB Piezotronics 640B01 contains a ceramic shear-mode piezoelectric sensing element that responds to acceleration of the machine surface. Internal electronics integrate the acceleration signal to velocity, detect the overall peak level in the band from 3 to 1,000 Hz (180 to 60,000 cpm) within ±10%, and convert that value into a 4-20 mA current. In general, overall velocity in this band is the quantity most commonly used for vibration severity assessment of general-purpose rotating machines, so the output can be compared directly against alarm and trip limits set by the plant.
The transmitter is a two-wire device powered from the loop at 12 to 30 VDC, and the maximum load resistance is given by the datasheet formula of 50 x (Vs – 12) ohms. The datasheet notes that the current output will fluctuate at frequencies below 5 Hz, and that the output settles within 2% of value in under 15 seconds after power-up, which should be considered when configuring PLC alarm delays.
Engineering Design of the PCB Piezotronics 640B01
Mechanically the PCB Piezotronics 640B01 has a 1.0 in (25.4 mm) hex, a height of 2.6 in (66 mm) and a weight of 4.7 oz (131 g). It mounts on a 1/4-28 UNF thread at 3 to 5 ft-lb (4 to 7 Nm) and is built from stainless steel with a welded hermetic seal, giving an IP68 enclosure rating and an operating temperature of -40 to +85 °C. The standard connector is a top-exit 2-pin MIL-C-5015, with pin A as 4-20 mA positive and pin B as 4-20 mA negative, and case isolation exceeds 108 ohm.
The datasheet lists useful options. The RV option adds a buffered dynamic acceleration output at 100 mV/g (±20%) and the RVVO option adds a buffered velocity output at 100 mV/in/sec (±20%), both through a 3-pin MIL-C-5015 connector, so that an analyst can plug in a portable collector for spectrum analysis while the 4-20 mA signal continues to feed the control system. An M option supplies an M081A61 stud adapter for metric holes and an EX option is offered for hazardous areas, with approvals confirmed by the factory.
When planning a loop, it is generally good practice to use shielded twisted-pair cable, ground the shield at the control panel end only and keep sensor cables separate from motor power wiring. The PCB Piezotronics 640B01 should be stud mounted in a drilled and tapped hole on the bearing housing, in the direction where the highest vibration is expected, which for most horizontal machines is the horizontal radial direction.
Key Features
Highlights of the PCB Piezotronics 640B01 include:
- A 4-20 mA output proportional to 0 to 25.4 mm/s peak velocity connects directly to PLC and DCS analog inputs.
- A frequency range of 3 to 1,000 Hz (±10%) covers typical running speed related faults on general-purpose machines.
- Broadband resolution of 0.13 mm/s pk and non-linearity of ±1%.
- Loop power from 12 to 30 VDC removes the need for separate signal conditioning.
- Welded hermetic stainless steel construction with an IP68 rating for outdoor and wash-down locations.
- Operating temperature range of -40 to +85 °C.
- Optional buffered dynamic outputs (RV or RVVO) allow route-based analysis from the same mounting point.
- Supplied with a Model 081A40 mounting stud and an NIST-traceable ICS-4 calibration for 4-20 mA sensors.
Industrial Applications
The PCB Piezotronics 640B01 is a natural fit for balance-of-plant machines that justify continuous protection but not a full monitoring rack: cooling water and firewater pumps, air handling units, cooling tower fans, blowers in wastewater treatment, and motor-pump sets in desalination and pumping stations. Plants in Muscat, Sohar and Salalah often add these transmitters to existing PLC I/O, so a vibration alarm can be raised on the same HMI that already shows pressure, flow and motor current. This approach is common in district cooling, water distribution and utility buildings where operators need a simple high-vibration alarm.
Seven Star LLC supplies the PCB Piezotronics 640B01 together with cables and accessories, and can also provide alternatives where the application needs them. For temperature and vibration in one compact device, see the Turck CMVT-QR20 vibration and temperature sensor; for a dynamic accelerometer with three axes, consider the PCB Piezotronics 356A01 tri-axial accelerometer; and where the signal should feed a dedicated protection system, the Bently Nevada 3500/20 rack interface module is part of a widely used rack platform.
Technical Specifications
The values below come from the PCB Piezotronics 640B01 datasheet, revision G:
| Parameter | Specification |
|---|---|
| Model | 640B01 |
| Type | Platinum 4-20 mA velocity transmitter |
| Measurement range | 0 to 1 in/sec pk (0 to 25.4 mm/s pk) |
| Output | 4-20 mA |
| Frequency range (±10%) | 3 to 1,000 Hz (180 to 60,000 cpm) |
| Broadband resolution | 0.13 mm/s pk (typical) |
| Non-linearity | ±1% |
| Temperature range | -40 to +85 °C |
| Enclosure rating | IP68 |
| Excitation voltage | 12 to 30 VDC |
| Load resistance | 50 x (Vs – 12) ohms |
| Settling time | below 15 s (within 2% of value) |
| Electrical isolation (case) | above 108 ohm |
| Sensing element / geometry | Ceramic / shear |
| Housing / sealing | Stainless steel / welded hermetic |
| Size (hex x height) | 25.4 mm x 66 mm |
| Weight | 131 g |
| Mounting thread / torque | 1/4-28 UNF / 4 to 7 Nm |
| Connector | 2-pin MIL-C-5015, top exit |
| Options | EX, M metric mount, RV acceleration output, RVVO velocity output |
How to Order
Contact Seven Star LLC to quote the PCB Piezotronics 640B01 or its RV, RVVO and M variants. Please include the number of points, cable lengths and the control system the transmitters will connect to. You can download the PCB Piezotronics 640B01 datasheet from this page, and our instrumentation team in Muscat will confirm availability and lead time and support installation and loop checks across Oman and the GCC.
- Datasheet PCB Piezotronics 640B01 Datasheet (Rev. G) Download
PCB sensors listed here
Model 356A01 is a miniature triaxial ICP accelerometer with a ceramic shear element and titanium housing. PCB gives it a nominal sensitivity of 5 mV/g, a range of 1000 g peak and a weight of about one gram; it is adhesive mounted and has an integral four-conductor cable. Model 378B02 is a 1/2-inch prepolarized free-field microphone supplied with a mated ICP preamplifier and TEDS, at 50 mV/Pa.Ordering PCB sensors: what we need
Send the exact model number, including any prefix letters. PCB puts option codes in front of the base model, so a high-temperature or metric version carries a different prefix. Add the cable length and connector, and the signal conditioner or analyzer input you are using. For GCC test laboratories we can request the manufacturer's calibration certificate with the sensor.Browse PCB Piezotronics products by category: Vibration.
Reviews
There are no reviews yet.