Bently Nevada 21505-00-28-10-02 Proximity Probe

21505-00-28-10-02 8mm Vibration Sensor with Armored Lead

Product Introduction

The 21505-00-28-10-02 belongs to Bently Nevada’s renowned 7200 series. This proximity transducer system measures shaft vibration and axial position in turbines, compressors, and large pumps. It features an 8-mm tip diameter and a stainless steel lead armor, offering superior mechanical protection in harsh industrial environments. The calibrated range extends to 80 mils, beginning at 10 mils from the probe face. With a scale factor of 200 mV/mil, this sensor delivers high-resolution data for condition monitoring applications. The unit includes a miniature male coaxial connector (Option 02) for reliable signal transmission. Additionally, the overall case length is 2.8 inches, while the total cable length reaches 1.0 meter. This model suits installations where both durability and measurement accuracy are critical.

Technical Specifications

The Bently Nevada 21505-00-28-10-02 operates on a DC input from -17.5 V to -26 V, drawing a maximum of 12 mA. Its output scale factor is 200 mV/mil (±4% when system-calibrated), and linearity stays within 0.8 mils under system calibration. Frequency response spans 0 to 10 kHz, with only a -5% deviation at 10 kHz. Temperature sensitivity typically changes by -3% at +150°F (+65°C) and a 50-mil gap. The unthreaded length is 0 mm, and the overall case length measures 2.8 inches. This model features a miniature male coaxial connector, simplifying integration with existing monitoring systems. The probe diameter is 8 mm, and the standard case construction ensures long-term reliability. Furthermore, the stainless steel lead armor protects against abrasion and mechanical stress.

Mechanical and Environmental Limits

This Bently Nevada probe withstands extreme operating conditions. The Proximitor functions between -60°F and +212°F, while the probe and cable handle -30°F to +350°F. Relative humidity up to 95% non-condensing is acceptable. Moreover, the 8-mm probe resists corrosion from air, water, lube oil, ammonium hydroxide, 10% sulfuric acid, MEK, and DMF. The total system weight is 1.3 lbs (0.59 kg). These characteristics make the 21505-00-28-10-02 ideal for steam turbines, centrifugal compressors, cooling tower fans, and other high-vibration rotating equipment.

Installation Guidelines

Mount the 21505-00-28-10-02 using the 3/8-24 thread, ensuring the air gap falls within the 10-to-90 mil range for optimum linearity. First, clean the mounting surface and bracket thoroughly to eliminate any debris. Next, attach the miniature coaxial connector to the extension cable, then tighten it securely. After that, route the armored lead along protected pathways, using clamps to prevent strain or movement. For the highest accuracy, calibrate the entire system—probe, cable, and Proximitor—as a single unit. Finally, connect the power supply to a stable -24 Vdc source, respecting the 12 mA maximum. Keep the cable away from high-voltage lines to minimize electrical noise interference.

Packaging and Shipping

Your order for the 21505-00-28-10-02 includes one Proximity Probe with armored lead, one Proximitor, and one extension cable with coaxial connectors. The package also contains mounting hardware and installation instructions. Every component arrives in factory-sealed anti-static packaging. We ship via FedEx, UPS, or DHL with full tracking and insurance coverage. Delivery typically takes 3–5 business days, depending on your location.

Frequently Asked Questions

Q1: What is the calibrated range of the 21505-00-28-10-02?
A1: The calibrated range is 80 mils (2.0 mm), beginning at 10 mils from the probe face.

Q2: Does this probe include a connector?
A2: Yes, it comes with a miniature male coaxial connector (Option 02) for easy system integration.

Q3: Why does this model have lead armor?
A3: The stainless steel armor protects the cable from mechanical damage, abrasion, and harsh environmental conditions.

Q4: Can I operate this probe with a -24 Vdc power supply?
A4: Yes, the input range is -17.5 Vdc to -26 Vdc, making -24 Vdc fully compatible.

Q5: Is the 21505-00-28-10-02 interchangeable with other 8mm probes?
A5: Yes, but interchangeability may widen linearity to ±2.3 mils. For best results, calibrate the complete system together.