1. Purpose

This document provides a step-by-step calibration procedure for the HGS-100 VCM (Polytron 8000) Gas Detector to ensure accurate measurement and proper functionality.

2. Required Tools and Equipment

• Calibration Gas (Zero and Span Gas)
• Magnetic Wand (for menu navigation)
• Multimeter (if needed)
• 6mm OD Tubing
• HGS-100C Control Unit

3. Calibration Procedure

Step 1: Enter Calibration Mode

1. On the HGS-100C Control Unit, navigate to the menu:
   • F4.UTIL → F1.DT.MOD → F2.DT.CAL → Input password (1234) → Enter detector number → Press "↵".

2. Select the corresponding detector number based on the gas type:

• • No.3: %LEL Gas Detector
  • No.4: VCM Gas Detector
  • No.5: NH₃ Gas Detector
  • No.6: %VOL Gas Detector

Step 2: Zero Calibration

      1. Tap ▼ (down) and hold with the magnetic wand for over 3 seconds to request the password.

      2. Enter password: OK → OK → OK → UP → UP

      3. Navigate to Calibration → Zero Calibration and select Apply Zero Gas → Press Next.

      4. Wait for stabilization and when prompted with Val. stabilized?, select Calibrate.

      5. If the displayed value is approximately 0% LEL, select Next.

      6. When prompted with Value out of alarm range?, select Next.

Step 3: Span Calibration

      1. Select Calibration → Span Calibration.

        2. Select the appropriate gas concentration:

1. • Methane 50% LEL (2.5% Vol) = 63.4% LEL
   • Propane 50% LEL (1.05% Vol) = 43.9% LEL    

        3. Adjust the gas value using ▲, ▼, and OK buttons.

        4. On the Apply Span Gas screen, select Next.

        5. Turn the 3-way ball valve to calibration mode and connect the regulator (O.D 6mm tubing).

        6. Insert span gas for 2 minutes and wait for stabilization.

         7. When prompted with Val. stabilized?, verify that the detector reading matches the span gas                       concentration and press Calibrate → OK.

        8. If the displayed value matches the expected gas concentration, select Next.

         9. If the % LEL value is lower than 5% LEL, select Next.

Step 4: Exit Calibration Mode

1. Select Exit, Save Configuration on the HGS-100C Control Unit LCD display.
2. Press Enter "↵", then press NO key "F4", and confirm with Enter "↵".
3. Press RETURN Key "F6" three times repeatedly to exit the menu.

⚠️ Caution: Return all valves to their original position after calibration.

4. Post-Calibration Verification

• Verify the detector readings are within the expected range.
• Ensure the gas detector alarm thresholds function correctly.