Schreiber SM30 LVDT sensor – Integrated electronics M30×1.5

The Schreiber SM30 series has eight electrical models. Each one determines the type of output signal and the direction of variation with respect to the core's movement.

Growing signal: It increases when the stem moves toward the sensor connector. The decreasing version reverses this relationship.

To connect the SM30 directly to an analog PLC input, you must check that the input supports the selected signal and that the power supply meets the reference requirements.

The Schreiber order code identifies the electrical model, nominal stroke, linearity class, and, where applicable, a mechanical option.

Structure: SM30X.STROKE.LINEARITY.OPTION

• X = 1 to 8: output type and signal direction.
• Career: 5, 10 or 15 mm.
• Class .1: linearity 0.25 %.
• Class .2: linearity 0.5 %.
• Option .T: execution as a prober.
• Option B: bellows execution.

The following table details the code combinations for standard mobile kernel versions. These combinations are based on the nomenclature in the datasheet; however, the acceptance of each combination and its commercial availability should be confirmed with the price list or the manufacturer.

Example expressly documented by Schreiber: SM303.10.2, 10 mm sensor, 4–20 mA incremental output and 0.5 linearity %.

Another example of the order structure is SM301.10.2.T, with probe execution. For mechanical modifications and special versions, Schreiber can assign specific order codes.

The SM30 incorporates a M30×1.5 threaded cylindrical housing with wrench tightening zones SW27. The main body has a nominal length of 70 mm according to the plan in the technical data sheet.

The standard version rod has a diameter of 16 mm in the area indicated by the plan and a threaded end M4 at the end. The dimensions must be checked on the drawing corresponding to the selected variant, especially when a probe or bellows is requested.

The casing is constructed of nickel-plated brass; The stem is made of stainless steel and the core of a Ni-Fe alloy. The connector is made of nickel-plated brass and its contacts are made of gold-plated brass.

The threaded mounting allows the sensor's position within the holder to be adjusted and kept aligned with the movement being measured. In a precision installation, it is important to avoid lateral stress on the rod.

The SM30 family offers optional mechanical configurations designed for different types of contact and protection:

• Version .T: implementation of a probe for direct measurement of the displacement of a part using a measuring tip.
• Version .B: execution with protective bellows around the moving assembly.

The Schreiber drawing shows the probe construction with a reference length of 55 mm from the body and a maximum indicated dimension of 63.5 mm for the protruding assembly. These dimensions belong to the drawing of version .T and should not be confused with the nominal measuring stroke.

To select the mechanical execution it is necessary to define the stroke, the available space, the contact geometry and the environmental conditions of the installation.

The SM30 has a four-pin electrical connector. The pin assignment depends on the output model. The Schreiber datasheet shows the connection as seen from the sensor's own connector.

Important: The SM305 and SM306 models require symmetrical power, while the remaining standard versions listed use a 20–32 VDC continuous power supply. The same power supply scheme should not be applied to all models.

The data sheet also specifies protection against reverse polarity of the power supply.

The SM30 series offers linearity classes of 0.5 % and 0.25 %, According to the reference. The integrated electronics convert the core displacement into a proportional current or voltage signal.

The documented general values are:

• Measurement frequency: 800 Hz, according to Schreiber's specifications.
• Thermal drift: less than 0.01 %/°C.
• Operating temperature: −20 to +85 °C.
• Vibration resistance: 20 g RMS, with peaks of 50 g.
• Shock resistance: 250 g SRS, 20–2000 Hz.
• Protection: IP66 with complementary connector mounted; the technical header also identifies IP66/IP67.

The manufacturer's reference conditions are an ambient temperature of +20 °C, the nominal power supply indicated for the version, and a stabilization period of 10 minutes after connecting the sensor.

The measurement frequency of 800 Hz should not be automatically interpreted as the maximum guaranteed response frequency of the entire system; for dynamic applications, it is advisable to check the acquisition and filtering conditions.

Current output versions SM301–SM304 They allow a load resistance of 0 to 500 Ω and have a specified maximum power consumption of 60 mA.

The documentation indicates a residual curl of less than 0.005 mA peak-to-peak, as well as a load dependence of less than 0.001 % for a change of 100 Ω and a power dependence of less than 0.05 % for a change of 1 V.

The voltage output versions SM305–SM308 require a load of at least 2 kΩ and have a maximum indicated consumption of 50 mA. Its residual ripple is less than 5 mV peak-to-peak.

For the SM307/SM308 versions, a maximum residual voltage of 0.1 VDC is indicated.

These features allow for the correct selection of PLC inputs, indicators, and data acquisition systems.

The SM30 is used as LVDT displacement sensor with integrated analog output in applications where it is important to obtain a proportional measurement without adding an external conditioner.

• Stroke control of actuators and linear mechanisms.
• Position measurement in industrial machines.
• Monitoring the movement of moving parts.
• Measurement of displacements on test benches.
• Dimensional control with probe configurations.
• Integration of analog sensors into PLCs and acquisition systems.
• OEM equipment and customized industrial solutions.

Among Schreiber sensors with integrated electronics, the SM31 series It incorporates programmable functions in a similar threaded format, while the SM32 series It uses a 25×25 mm square housing. For applications where a smaller diameter miniature body is needed, the SM34 series It offers another alternative in the range.

The selection should be made based on travel distance, dimensions, output signal, power supply, and installation requirements. GUEMISA can explore equivalencies with other analog output LVDT transducers when the original reference or datasheet is available.

The models SM303 and SM304 They provide 4–20 mA output. The SM303 has a rising signal and the SM304 a falling signal. Both require a 20–32 VDC power supply.

The models SM307 and SM308 They offer 0–10 VDC output. The SM307 is step-up and the SM308 is step-down. The specified supply voltage is 20–32 VDC.

Yes. The models SM305 and SM306 They provide ±10 VDC output and require symmetrical ±13 to ±16 VDC power supply.

No. The measurement electronics are integrated into the sensor and directly provide the analog output of the chosen reference, provided that a compatible power supply and acquisition input are used.

The manufacturer's technical data sheet documents nominal travels of 5, 10 and 15 mm, with linearity classes of 0.5 % or 0.25 % depending on the reference.

It is a Schreiber SM30 sensor with 4–20 mA scaling output, 10 mm nominal travel and 0.5 % linearity, according to the order example published by the manufacturer.

Yes. The documentation includes a version .T of a feeler and a version .B with bellows. Its configuration must be confirmed when defining the full reference.

GUEMISA Schreiber Messtechnik supplies sensors in Spain and offers technical advice for selecting the SM301–SM308 model, the travel, the output signal and the mounting configuration.