Unit 3 — Setup Procedures

TM-CAL-007 — Open Handout TM Chapter: Chapter 4 ELOs: Execute setup steps in correct sequence; verify readiness before calibration Estimated time: 15 minutes

Step 1: Read the TM

Open TM-CAL-007. Read Chapter 4 — Assembly Procedures completely.

Then come back here.

Chapter 4 Content

  1. Connect LM336Z-2.5 with 1kΩ bias resistor from supply positive to anode (+). Connect cathode (K) to positive output terminal. Ground is common.
  2. Connect 50kΩ trimmer between ADJ pin and a midpoint in the 10kΩ divider for fine adjustment.
  3. Build precision divider: for 1.000 V from 2.500 V use R1=1.5kΩ and R2=1.0kΩ (1.000/2.500 = 0.400 ratio; choose R2/(R1+R2) = 0.400).
  4. Add 100 nF C0G capacitor at each output to suppress HF noise.
  5. Verify all connections before applying power.
  6. Apply 9 V. Measure reference output. Adjust trimmer to exactly 2.500 V using reference DMM.

Setup is Part of Calibration

Chapter 4 specifies 6 setup steps.

A calibration is only valid if the setup is correct. Common setup errors that invalidate results: - Skipping warm-up time - Wrong input range or measurement mode selected - Reference connected to wrong terminal - Ground loops or interference from adjacent equipment

If Chapter 4 specifies a verification at the end of setup (e.g., "confirm instrument reads X before proceeding"), do it. That check exists because someone discovered a failure mode that made it necessary.

Self-Check Questions

SC3-1. How many steps does Chapter 4 specify for setup?

SC3-2. What is the first step? State it exactly from the TM.

SC3-3. Does Chapter 4 require any verification before proceeding to calibration? If so, state it.

SC3-4. What is the last step of Chapter 4 (immediately before you begin the Chapter 5 calibration)?

SC3-5. What would you do if a setup step produced an unexpected result?

Answer Key

SC3-1. Count the numbered steps in Chapter 4. The answer is in the TM.

SC3-2. See Chapter 4, step 1. Copy it exactly.

SC3-3. Scan Chapter 4 for steps containing "verify," "check," "confirm," or "measure." If present, they are hold points.

SC3-4. See the last numbered step in Chapter 4.

SC3-5. Stop. Do not proceed to calibration. Diagnose the unexpected result — it may indicate a setup error, a faulty reference, or a failed instrument under test.

Checkpoint

Before proceeding: - [ ] You have read Chapter 4 completely - [ ] You can state the number of setup steps - [ ] You understand setup errors invalidate calibration results

→ Proceed to Unit 4