The Matsushima PFM-M01E Dust Monitor (Compact Type) is an instrument designed to measure dust concentration in gas streams by detecting the electric charge generated when solid particles pass through its probe. This phenomenon, known as frictional static electricity or contact electrification, allows the device to quantify dust levels based on the electrical current produced, which is proportional to the amount of dust. The filtered and amplified current signal is then converted into an instrumentation signal (4mA to 20mA) and a contact signal, both proportional to the dust amount.
Function Description
The core function of the PFM-M01E Dust Monitor is to continuously measure the concentration of solid particles in gas. It operates on the tribo-electric charge detection method. When dust particles, such as talc, move past the probe, they generate an electric charge. This charge is converted into a current signal, which is then processed to provide an output signal (4-20mA) that directly correlates with the dust concentration. The device also includes alarm and limit contacts for process control and safety.
Important Technical Specifications
Power Supply:
- Voltage: AC 80V~240V, 50/60Hz
- Power Consumption: 4VA
Measurement:
- Material: Solid particles in gas
- Particle Type: All solid particles
- Dust Size: ≥ 0.3 µm
- Dust Concentration Range: 0.1mg/m³ ~ 1000mg/m³ (across 9 switchable ranges)
- Range 1: 0.1 ~ 1000mg/m³
- Range 2: 0.1 ~ 500mg/m³
- Range 3: 0.1 ~ 200mg/m³
- Range 4: 0.1 ~ 100mg/m³
- Range 5: 0.1 ~ 50mg/m³
- Range 6: 0.1 ~ 20mg/m³
- Range 7: 0.1 ~ 10mg/m³
- Range 8: 0.1 ~ 5mg/m³
- Range 9: 0.1 ~ 2mg/m³
- Principle: Tribo-electric charge detection method
Process Conditions:
- Temperature: ≤ 250°C
- Pressure: ≤ 200kPa
- Velocity: ≥ 4m/s
- Humidity: ≤ 40vol%
Ambient Conditions:
- Temperature: -20 ~ 65°C (Non-condensing)
- Humidity: ≤ 95%RH (Condition: State of case sealing up)
Output Signal:
- Analog Signal: DC 4~20mA × 1 (max. 23.3mA), Load: Max 500Ω (Isolated)
- Relay Output Signal:
- Alarm contact: 1b × 1 (AC250V, 2A/DC30V, 2A)
- Upper limit contact: 1a × 1 (AC250V, 2A/DC30V, 2A)
Mounting:
- R1 Screw (1" Socket)
- Flange mounting is available as an option.
Protection:
- IP65 (with the cover and cable gland tightened)
Physical Characteristics:
- Housing: Aluminum die-cast
- Probe: SUS316L
- Insulator: PTFE
Usage Features
Installation:
The Dust Monitor is installed using a one-inch socket, which is welded onto the pipe. It can be mounted horizontally or vertically, ensuring the weld around the pipe circumference prevents gas leakage. Specific attention is required for installation location to avoid malfunction, such as proximity to pipe flues, inflections, fans, or non-conductive ducts. The gap between the probe end and the pipe should be greater than 20mm. Proper cable gland usage and sealing are crucial to maintain the IP65 protective structure and prevent outside air or dust from entering the main unit. Silica gel is included for dehumidification and should not be removed.
Wiring:
The device features terminals for AC power (AC80-240V, 50/60Hz), Alarm contact (b contact, AC250V 2A, DC30V 2A), Limit contact (a contact, AC250V 2A, DC30V 2A), and 4-20mA output (DC4-20mA, Max500Ω). Line-connecting terminals support a maximum of 1.5mm² wire.
Operation Method:
The front panel includes a Range Switch, Mode Change Switch, and various LEDs (POWER, ALARM, LIMIT, LIMIT SET, I. TIME SET, VALUE DISPLAY) and adjustment volumes (Upper Limit Setting, Integration Setting, 4mA, 20mA).
- Warming-up: The monitor requires approximately one hour of warming up after power-on for stable operation.
- Measuring Range Selection: The Range Switch allows selection from 9 different measuring ranges (1-9). Range 0 is reserved for Maintenance Mode. The choice of range depends on the flow speed, filter operation, and environmental conditions. For finer changes, ranges 5-9 are used, while ranges 1-4 are for broader measurements.
- Density Interpretation: The output value is influenced by particle type, diameter, gravity, and flow speed. The device uses "talc" as a standard powder, with 20mA output corresponding to 1000 mg/m³ at 10 m/s flow speed. Users must determine the density corresponding to 0% to 100% signals for their specific application and adjust the range or integral function accordingly to obtain an optimal current signal.
Integral Setting:
The Dust Monitor can output an averaged measuring signal by adjusting the Integration Volume (Data averaging).
- Set the Range Switch to "0".
- Press the Mode Change Switch until the "I.TIME SET" LED lights up.
- Turn the Integration Volume clockwise to set the desired integral time (each LED lamp on the display represents three seconds, up to 30 seconds max).
- Change the Range Switch to a value other than "0" to complete the setting. Turning the volume fully counterclockwise sets the integral time to 0 seconds.
- For detailed setting, a tester can be connected to the 4-20mA output terminal.
Limit Setting:
The upper limit point (contact output point) can be set within the 4mA (0%) to 20mA (100%) range.
- Set the Range Switch to "0".
- Press the Mode Change Switch until the "LIMIT SET" LED lights up.
- Turn the Limit Setting Volume clockwise to set the desired limit (each LED lamp represents 10%, up to 100% max).
- Change the Range Switch to a value other than "0" to complete the setting. Turning the volume fully counterclockwise sets the alarm output at 4mA (0%) or more.
- For detailed setting, a tester can be connected to the 4-20mA output terminal.
- Alarm Operation: The alarm contact is open and the LED is off if there is no power supply. In normal operation, the NC (close) LED is off. At breakdown, the NC (open) LED is lit.
Maintenance Features
Routine Maintenance:
- Probe Cleaning: The probe should be periodically cleaned with a rag. The recommended cleaning frequency is at least once every three months, depending on the measured material and conditions.
- Safety Precautions: Always turn off the power before cleaning. Be careful not to burn yourself when removing the probe. The earth line must not be removed during maintenance to prevent faults.
- Probe Handling: Do not directly touch the probe with bare hands, even when power is off, to avoid static electricity damage. Use non-conductive gloves (e.g., rubber gloves) when handling the probe during installation or maintenance. Clean the probe with a moist cloth; dry cloths may generate friction charge.
Maintenance Mode (Range Switch "0"):
This mode allows for confirmation and adjustment of various parameters:
- Current Signal Adjustment:
- Set Range Switch to "0" while pressing the Mode Change Switch.
- Keep pressing the Mode Change Switch for more than five seconds until "LIMIT SET" and "I.TIME SET" LEDs light up.
- Release the Mode Change Switch; 4mA will be forced to output. Adjust with the 4mA Volume if necessary.
- Press the Mode Change Switch again; 20mA will be forced to output. Adjust with the 20mA Volume if necessary.
- Subsequent presses of the Mode Change Switch alternate between 4mA and 20mA output.
- Change the Range Switch to a value other than "0" to return to normal setting mode.
- Limit and Integration Confirmation:
- Set Range Switch to "0".
- Press the Mode Change Switch once; the "LIMIT SET" LED lights up, allowing limit setting adjustment via the "LIMIT adj." Volume.
- Press the Mode Change Switch again; the "LIMIT SET" LED goes out, and the "I.TIME SET" LED lights up, allowing integral setting adjustment via the "I TIME adj." Volume.
- Subsequent presses of the Mode Change Switch alternate between limit and integral setting.
- Change the Range Switch to a value other than "0" to return to normal setting mode.
- Alarm Output Simulation: In Maintenance Mode, the "Alarm" LED (red) lights up, and an alarm contact is output. This feature is useful for loop checks during trial operations. However, switching to Maintenance Mode during normal operation will trigger an alarm signal, so caution is advised.
- Power Reset: After switching from Maintenance Mode to Measurement Mode, the power supply must be reset.
Troubleshooting:
The manual provides a troubleshooting guide for common malfunctions:
- No LED lights up: Check power supply connection and specifications.
- Output value fluctuates: Check if the device is warmed up, grounded, cable connections, and if any material or condensation is on the electrode surface.
- Output value too high: Check for short-circuits due to material on the electrode, condensation, or if the electrode touches the inner pipe surface. Ensure insulation is sufficient (at least 10mm out of the socket). If the probe is too short, electric charge detection may be incorrect.
- Output value does not change: Check power supply, cable connections, material/condensation on the electrode, and if the electrode touches the inner pipe surface.
- Alarm LED lights up: Check if the device is in Maintenance Mode or if there is a device failure.
The Matsushima PFM-M01E is a robust and versatile dust monitor designed for reliable operation in industrial environments, providing essential data for process control and environmental monitoring.
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