Q: How can we prevent a diffuse reflection photoelectric sensor from falsely detecting background objects outside of its sensing range?
A: As a first step, we should verify if the falsely detected background has a "high-brightness reflective" property.
High-brightness reflective background objects can interfere with the operation of diffuse reflection photoelectric sensors. They cause false reflections, leading to incorrect sensor readings. Moreover, high-brightness reflective backgrounds can also interfere with both diffuse reflection and background suppression photoelectric sensors to some extent.
PSE-PM1-V Polarized reflection Photoelectric sensor
Sensing distance: 1m (non-adjustable)
Output mode: NPN/PNP NO/NC
Light source: VCSEL light source
Spot size: approximately 3mm @ 50cm
PSE-YC-V Background suppression Photoelectric sensor
Sensing distance: 15cm (adjustable)
Output mode: NPN/PNP NO/NC
Light source: VCSEL light source
Spot size: <3mm @ 15cm
Q:Determination of frequency and sensor selection based on rotational speed
A:Frequency can be calculated using the following formula: f(frequency) Hz = RPM / 60s * number of teeth.
•Sensor selection should consider both the calculated frequency and the gear's tooth pitch.
Frequency-Time Reference Chart
| Frequency | Cycle (response time) |
| 1Hz | 1S |
| 1000Hz | 1ms |
| 500Hz | 2ms |
| 100Hz | 10ms |
Nominal Frequency:
For inductive and capacitive sensors, the target gear should be positioned at 1/2Sn (ensuring that the distance between each tooth is ≤ 1/2Sn). Use a frequency test fixture to test and record the frequency value of 1 cycle using an oscilloscope (for accuracy, record the frequency of 5 cycles and then calculate the average). It should meet the requirements of 1.17 (if the nominal operating distance (Sa) of the proximity switch is less than 10mm, the turntable should have at least 10 targets; if the nominal operating distance is greater than 10mm, the turntable should have at least 6 targets).
M12/M18/M30 Frequency inductive sensor
Sensing distance：2mm、4mm、5mm、8mm
Switching frequency [F]：1500Hz、2000Hz、4000Hz、3000Hz
10-30VDC NPN/PNP NO/NC
Protection degree IP67 (IEC).
Frequency up to 25KHz.
Long life and high reliability.
Sensing distance 2mm
M18 metal cylindrical type, NPN/PNP output
Detection distance: 2mm
Protection degree IP67 (IEC)
,Frequency up to 25KHz
Q:When a pipeline level sensor is used to detect the liquid level in a hose, the sensing is unstable. What should I do?
A:First, check if there is a half-sided adhesive label on the hose. If only half of the hose is labeled, it will cause a difference in dielectric constant, resulting in unstable sensing as the hose rotates.
Dielectric Constant:
The dielectric constant reflects the relative ability of a dielectric material to store electrostatic energy in an electric field. For dielectric materials, the lower the relative dielectric constant, the better the insulation.
Example: Water has a dielectric constant of 80, while plastics typically have a dielectric constant between 3 and 5. The dielectric constant reflects a material's polarization in an electric field. A higher dielectric constant indicates a stronger response to an electric field.
Sensing distance：6mm
Can detect metal and non-metal material objects, more widely used.
Response frequency up to 100Hz.
Fast and accurate sensitivity adjustment with multi-turn potentiometer.
Q:How to select sensors for particle feed detection in the livestock industry?
A:The presence of gaps between individual particles in granular feed reduces the effective contact area with the sensing surface, resulting in lower dielectric properties compared to powdered feed.
Note: Pay attention to the moisture content of the feed during sensor operation. Excessive moisture in the feed can lead to long-term adhesion to the sensor surface, causing the sensor to remain in a constant on state.
Sensing distance: 15mm (adjustable)
Housing size: φ32*80 mm
Wiring:AC 20…250 VAC relay output
Housing material:PBT
Connection: 2m PVC Cable
Sensing distance: 15mm, 25mm
Mounting: Flush/ Non-flush
Housing size: 30mm diameter
Housing material: Nickel-copper alloy/ plastic PBT
Output: NPN,PNP, DC 3 /4 wires
Output indication:Yellow LED
Connection: 2m PVC Cable/ M12 4-pin connector
Post time: Dec-02-2024