21505-24-40-10-02 Bently Nevada 8mm Armored Sensor

Bently Nevada 21505-24-40-10-02 Armored Proximity Probe for Demanding Applications

Product Introduction

The Bently Nevada 21505-24-40-10-02 is a rugged proximity probe from the 7200 series. Unlike standard probes, this model comes with stainless steel lead armor. This armor protects the cable from abrasion, cutting, and chemical exposure. Many users select Bently Nevada when their installation requires extra mechanical protection.

The 21505-24-40-10-02 measures shaft vibration, thrust position, and eccentricity. Its unthreaded length reaches 2.4 inches, providing flexible gap adjustment. Meanwhile, the overall case length is 4.0 inches. This longer case suits deep mounting holes or custom brackets. Furthermore, the armored lead prevents damage during installation and machine operation.

Technical Specifications

Input Power Requirements: The system needs -17.5 Vdc to -26 Vdc at 12 mA maximum consumption.

Output Calibration Range: Calibrated range is 80 mils (2.0 mm). Measurement begins at approximately 10 mils (0.25 mm) from the probe face.

Scale Factor Accuracy: Standard output is 200 mV/mil (7.87 V/mm). System calibration gives ±4% accuracy measured in 10 mil increments. When you include interchangeability errors, accuracy stays within ±9.5%.

Linearity Performance: System calibration keeps linearity within 0.8 mils (0.02 mm) of the 200 mV/mil straight line. Including probe interchangeability, the deviation extends to 2.3 mils (0.06 mm).

Frequency Response: The sensor responds from 0 to 10 kHz (0 to 600,000 cpm). At the maximum 10 kHz point, response drops by only -5%.

Temperature Sensitivity: At +150°F (+65°C) with a 50 mils gap (1.27 mm), the scale factor changes by approximately -3%.

Mechanical and Environmental Limits

Operating Temperatures:

• Proximitor: -60°F to +212°F (-51°C to +100°C)

• Probe and extension cable: -30°F to +350°F (-34°C to +177°C)

Humidity Tolerance: The system handles up to 95% relative humidity, noncondensing.

Corrosion Resistance for 8 mm Probes: Direct contact with air, water, lube oil, ammonium hydroxide, 10% sulfuric acid, MEK (methyl-ethyl ketone), or DMF (dimethylformamide) does not affect operation.

Tip Construction and Ordering Breakdown

Tip Construction Details for 21505-24-40-10-02

• Part number base: 21505

• Diameter: 8 mm

• Case type: Standard

• Thread configuration: 3/8-24

• Lead armor: Yes (stainless steel)

How to Read Your Ordering Code

• Unthreaded length option 24 = 2.4 inches

• Overall case length option 40 = 4.0 inches

• Total length option 10 = 1.0 metre (39 inches). Tolerance: +0.25 metre, -0.10 metre

• Connector option 02 = Miniature male coaxial connector

Installation Guidelines

First, inspect the mounting hole depth before installing the Bently Nevada 21505-24-40-10-02. The 2.4 inch unthreaded section gives you significant positioning flexibility. Next, route the armored cable carefully to avoid sharp bends. The stainless steel armor resists crushing, but excessive bending may damage internal wires.

Meanwhile, set the initial gap to approximately 10 mils (0.25 mm) from the shaft surface. Use a precision gap tool or monitor the output voltage. The longer 4.0 inch case helps when you need to reach past obstacles. Additionally, secure the miniature male coaxial connector to prevent signal noise. Finally, verify the gap voltage before running the machine at full speed.

Packaging List

• One Bently Nevada 21505-24-40-10-02 proximity probe with stainless steel lead armor

• Factory original anti-static packaging

• No mounting hardware, extension cables, or Proximitor included

Note: Extension cables and the Proximitor driver must be ordered separately.

Shipping Information

All orders ship via Fedex, UPS, or DHL. Tracking numbers are provided within 24 hours of dispatch.

Frequently Asked Questions (FAQ)

1. Why does the 21505-24-40-10-02 have stainless steel lead armor?
The armor protects the cable from mechanical damage. For instance, sharp edges, hot surfaces, or moving parts can cut unprotected cables. The stainless steel armor prevents this and extends sensor life in harsh environments.

2. What is the difference between unthreaded length and case length on this probe?
Unthreaded length (2.4 inches) is the smooth section between the threads and the tip. Overall case length (4.0 inches) includes the threaded section plus the unthreaded portion. Both dimensions affect how deep the probe sits in your mounting hole.

3. Can I use the Bently Nevada 21505-24-40-10-02 without an extension cable?
Yes, but the total length is only 1.0 metre. For longer distances between the probe and Proximitor, you need an extension cable. The miniature male coaxial connector on this probe mates with standard Bently Nevada extension cables.

4. How does the armored lead affect installation compared to non-armored probes?
The armored lead is stiffer and heavier. You need larger bend radii during routing. However, this stiffness also means the cable holds its shape better and resists accidental pulling. Plan your cable path before securing the probe.

5. Is this probe compatible with the same Proximitor as other 8 mm Bently Nevada sensors?
Yes, the 21505-24-40-10-02 works with standard Bently Nevada 7200 series Proximitors. It shares the same 200 mV/mil scale factor and 80 mil calibrated range. Always verify your specific Proximitor model supports 8 mm probes before connection.