IQS450 204-450-000-001-A1-B22-H05-I0 Signal Conditioner

The IQS450 204-450-000-001-A1-B22-H05-I0 is an industrial-grade non-contact eddy current displacement measuring system from Vibro-Meter. It is specifically designed for highly reliable and stable vibration and displacement monitoring of rotating machinery under demanding operating conditions. Its core features include the use of a 2-wire 4-20mA current output (Ordering Option B22) and a 5-meter total system cable length (Ordering Option H05). This makes it particularly well-suited for industrial applications requiring long-distance signal transmission, strong resistance to electromagnetic interference (EMI), and simplified wiring systems.

Based on the proven eddy current principle, the system provides continuous and precise measurement of mechanical shaft radial vibration and axial position through the precise pairing and calibration of the TQ 402/412 series proximity transducer and the IQS 450 signal conditioner. The current output mode (B22) offers significant advantages in noise immunity and permits longer transmission distances without signal degradation (up to 1000 meters with safety barriers/isolators) compared to voltage mode. It is also less susceptible to line voltage drop, making it an ideal interface for connection to Distributed Control Systems (DCS), Programmable Logic Controllers (PLCs), and Safety Instrumented Systems (SIS).

This model is designed for standard industrial environments (A1), with explosion-proof versions (A2, A3) available for use in potentially explosive atmospheres. Its rugged mechanical construction, wide operating temperature range, and comprehensive international safety certifications ensure exceptional performance and long-term reliability in critical machinery protection applications across industries such as power generation, petrochemicals, metallurgy, and heavy machinery.

Core Value Proposition:

• Robust Current Loop Signal: Option B22 provides a 4-20mA analog current output, inherently noise-immune and ideal for reliable long-distance transmission in complex electromagnetic environments.

• Excellent System Integration: Directly compatible with standard industrial process control I/O cards, simplifying system design and wiring.

• Superior Interchangeability & Stability: Transducer and conditioner components are interchangeable without requiring recalibration, significantly reducing maintenance complexity and spare parts costs.

• 5-Meter Standard Length (H05): Offers a balance between installation flexibility and signal integrity, suitable for typical scenarios where sensor distance to cabinet is moderate.

• Comprehensive Safety Assurance: Design follows international standards like API 670, with optional ATEX/CSA explosion-proof certifications for safe use in hazardous areas.

2. System Operating Principle & B22 Output Characteristics

The system operates based on the eddy current effect. The IQS 450 conditioner supplies a high-frequency excitation signal to the transducer coil, which generates an alternating magnetic field. When this field approaches a metal target, induced eddy currents change the coil's impedance. This impedance change is closely related to the air gap distance between the transducer and the target.

For the B22 current output mode, the internal circuitry of the IQS 450 converts the transducer's impedance change into a 2-wire DC current signal. Its unique features are:

1. Two-Wire System: The same pair of wires provides the -24VDC operating power to the conditioner and carries the output measurement current signal, greatly simplifying wiring.

2. 4-20mA "Suppressed-Zero" Output: Within the standard 0.15-2.15mm linear range, the output current is mapped to the 15.5mA to 20.5mA interval, not the full 4-20mA range. This effectively "amplifies" the effective measuring range into a ~5mA current window, thereby achieving higher output resolution and system sensitivity (2.5 μA/μm). For example, a tiny 1-micron gap change will produce a measurable 2.5 microamp current change, which is crucial for precise monitoring of minute vibrations or displacement.

3. Fault Indication: Following the 4-20mA standard, an output current below 4mA (e.g., 3.8mA) or above 20.5mA can be recognized by the host system as an abnormal condition such as sensor wire break, short circuit, or power failure.

The advantage of a current signal lies in its strong noise immunity and independence from voltage drops caused by line resistance, making it highly suitable for transmission over distances ranging from tens to hundreds of meters. It is one of the most common analog signal standards in industrial fieldbuses and DCS systems.

3. Typical Applications & Advantages of H05 Cable Length

Application Fields:

• Oil & Gas: Shaft vibration monitoring for pipeline compressors, offshore platform gas turbines, refinery wet gas compressors.

• Power Generation: Bearing vibration and axial position protection for steam turbine generators, gas turbines, boiler feedwater pumps.

• Chemical Processing: Condition monitoring for high-speed centrifugal compressors, large reciprocating compressors, reactor agitators.

• Heavy Industry: Machinery protection for rolling mills, large fans, mining crushers.

Advantages of the 5-meter Total Length (H05) Configuration:
This length is one of the "gold standards" in industrial settings because it:

1. Provides Ample Installation Freedom: Sufficient to route the cable from the transducer inside a casing to a nearby junction box or bulkhead, allowing reasonable slack for installation.

2. Optimizes Signal Integrity: Maximizes transmission capability while minimizing potential signal attenuation and high-frequency response limitations associated with very long cables.

3. Meets Minimum TSL Requirement: The minimum allowed length for a 5-meter system is 4.4 meters, providing flexibility for on-site electrical "trimming" of the cable and installation tolerances.

4. Balances Cost and Practicality: Avoids the increased cost, installation complexity, and potential interference risks associated with excessively long cables.

4. Installation, Wiring & Commissioning Guide

1. System Configuration Overview:
For a typical B22 current output system, the signal chain is usually:
TQ Transducer → (Optional: EA 402 Extension Cable) → IQS 450 Conditioner (set to B22 current mode) → 2-core shielded cable (e.g., K 209/K 210) → **Safety Barrier/Isolator (GSI 124, for explosion-proof or long-distance transmission)** → DCS/PLC AI Card (input impedance 250Ω)

2. Key Installation Steps:

• Mechanical Installation: Strictly adhere to the geometric constraints in the manual. Set the initial mechanical gap using feeler gauges. For vibration monitoring, setting it near the middle of the linear range (~1.15mm), corresponding to an output current of ~18.0mA, is recommended.

• Cable Handling: Never cut or splice cables. Secure the 5-meter cable properly at 100-200mm intervals to prevent vibration. Observe the minimum bending radius.

• Electrical Wiring:

• Connect the IQS 450's "-24V" and "COM" terminals to the DC power loop from the GSI 124 safety barrier (or power supply).

• The IQS 450's "OUTPUT" terminal is the current signal output, to be connected to the "+/-" input of the GSI 124.

• Single-Point Shield Grounding: Typically grounded at the safety barrier or control system cabinet side to prevent ground loops.

3. Power-Up, Commissioning & Verification:

• Loop Check: Verify that the total current loop impedance (cable resistance + barrier internal resistance + AI card resistance) does not exceed the limit for the given supply voltage.

• Static Verification: With the machine stationary, measure the loop current in series with a high-precision milliammeter. This value should be between 15.5-20.5mA and correspond to the estimated value based on the mechanically set initial gap.

• Dynamic Test (Optional): Gently tap the transducer mounting base or target shaft; the vibration value displayed on the monitoring system should change accordingly.

4. Critical Role of the Safety Barrier (GSI 124):
When used in explosive atmospheres or for long-distance transmission, the GSI 124 is an essential component. It:

• Provides intrinsically safe (Ex i) power to the IQS 450 in the hazardous area.

• Reads the 4-20mA current signal from the hazardous area.

• Outputs an isolated voltage signal (e.g., -1.6V to -17.6V corresponding to 15.5-20.5mA) proportional to the current on the safe area side for the control system to read.

• Provides energy isolation and signal transfer between the hazardous and safe areas.

5. Troubleshooting & Maintenance

• No Output or Very Low Output: Check power supply polarity and voltage; check for open circuit in the loop; check for transducer cable damage.

• Output Saturated (>20.5mA or <15.5mA): Check if the transducer is too close to or touching the target; check for severe contamination or damage to the transducer tip; check for significant difference between target material and calibration material.

• Excessive Signal Noise: Check shield integrity and correct single-point grounding; check if signal cables are routed parallel to power cables; check for loose or damp connections.

• Regular Maintenance: During inspections, check transducer tightness and cable condition; periodically clean oil/grease from the transducer tip; system performance can be re-tested during major overhauls.