Brunton OSS 30B Baseplate Compass User Manual

Introduction

This manual provides detailed instructions for the proper use, setup, maintenance, and troubleshooting of your Brunton OSS 30B Baseplate Compass. Designed for reliable navigation, this portable compass is an essential tool for outdoor enthusiasts, hikers, and navigators. Please read this manual thoroughly to ensure optimal performance and longevity of your device.

Product Overview

The Brunton OSS 30B Baseplate Compass is a precision instrument featuring several key components for accurate navigation.

Figure 1: Brunton OSS 30B Baseplate Compass. This image displays the top view of the compass, highlighting the clear baseplate, rotating bezel, magnetic needle, and various scales.

Key Components:

• Baseplate: A clear, durable plastic plate with rulers and scales for map work.
• Compass Housing (Bezel): A rotating dial marked with 360 degrees and cardinal directions (N, E, S, W).
• Magnetic Needle: The red (north) and white (south) needle that aligns with the Earth's magnetic field.
• Orienting Arrow and Lines: Lines inside the compass housing used to align with map grid lines or the magnetic needle.
• Direction of Travel Arrow: An arrow on the baseplate indicating the direction you intend to travel or the bearing you are taking.
• Declination Adjustment: A mechanism to compensate for the difference between true north and magnetic north.
• Rulers and Scales: Printed on the baseplate for measuring distances on maps.
• Lanyard Hole: For attaching a cord to keep the compass secure.

Setup

1. Attach Lanyard: Thread a lanyard through the designated hole on the baseplate. This helps prevent loss and allows for easy access.
2. Understand Declination: Magnetic declination is the angle between magnetic north (where your compass points) and true north (the direction of the North Pole). This angle varies depending on your location. Consult a local topographic map or an online resource to find the current declination for your area.
3. Adjust Declination (if applicable): The OSS 30B features a tool-free declination adjustment. To adjust, rotate the small screw or dial on the compass housing until the orienting arrow aligns with the correct declination value (east or west) relative to the 'N' on the bezel. This ensures your compass points to true north when the needle is aligned with the orienting arrow.

Operating Instructions

Taking a Bearing from a Map:

1. Place Compass on Map: Lay your map flat. Place the compass on the map so that the edge of the baseplate connects your current position (Point A) with your destination (Point B). Ensure the direction of travel arrow points from Point A to Point B.
2. Orient the Bezel: While keeping the baseplate fixed on the map, rotate the compass housing (bezel) until the orienting lines inside the housing are parallel with the north-south grid lines on your map. Ensure the 'N' on the bezel points towards the north of the map.
3. Read the Bearing: The number on the bezel that aligns with the direction of travel arrow is your magnetic bearing to the destination.

Following a Bearing in the Field:

1. Set the Bearing: Hold the compass level in front of you. Rotate your entire body until the red (north) end of the magnetic needle aligns perfectly with the orienting arrow inside the compass housing.
2. Identify a Landmark: Look up from the compass along the direction of travel arrow. Identify a distinct landmark (e.g., a tree, rock, distant peak) that lies directly in line with the arrow.
3. Walk to the Landmark: Walk to the chosen landmark. Once you reach it, repeat the process: align the needle, find a new landmark, and walk to it. Continue this until you reach your destination.

Using the Rulers and Scales:

The baseplate includes various rulers and scales (e.g., millimeters, inches, map scales like 1:24,000 or 1:50,000). These are used to measure distances on your map. Match the scale on your compass to the scale of your map for accurate distance calculations.

Maintenance

• Cleaning: Wipe the compass clean with a soft, damp cloth. Avoid abrasive cleaners or solvents that could damage the plastic or markings.
• Storage: Store your compass in a cool, dry place away from strong magnetic fields (e.g., magnets, electronic devices, car speakers) to prevent demagnetization of the needle.
• Avoid Impact: While durable, dropping the compass or subjecting it to strong impacts can affect its accuracy.
• Temperature Extremes: Avoid prolonged exposure to extreme temperatures, which can affect the liquid inside the housing and the needle's movement.

Troubleshooting

• Needle Sticking or Sluggish:

  Possible Cause: Exposure to extreme temperatures, air bubble in the liquid, or magnetic interference.

  Solution: Ensure the compass is level. Tap gently on the baseplate to dislodge the needle. Move away from any potential magnetic interference. If an air bubble is present, it usually does not affect accuracy unless it's very large and obstructs the needle's movement.

• Inaccurate Readings:

  Possible Cause: Magnetic interference, incorrect declination setting, or not holding the compass level.

  Solution: Move away from metal objects, power lines, or electronic devices. Verify your declination setting for your current location. Always hold the compass perfectly level for accurate readings.

• Difficulty with Declination Adjustment:

  Possible Cause: Mechanism is stiff or unfamiliarity with the adjustment method.

  Solution: Apply gentle, firm pressure when rotating the adjustment dial. Refer to the "Setup" section for detailed instructions on adjusting declination. If the mechanism is truly stuck, contact customer support.

Specifications

Warranty and Support

For information regarding warranty coverage, product support, or service, please refer to the documentation included with your purchase or visit the official Brunton website. Keep your proof of purchase for any warranty claims.

Brunton Official Website: www.brunton.com (Note: This is a placeholder URL as no specific support link was provided in the product data.)