CalibKeepr · Metrology Specifications

What the Calibrations Need to Be (SOPs & Tolerances)

Define the exact step-by-step checklist, target nominal values, +/- tolerances, ambient temperature/humidity limits, and master reference standards required for every tool family.

SOP-CAL-101 Dimensional Rev 4.2📜 ISO 13385-1:20192 tool(s) assigned

Digital & Dial Caliper 4-Point Dimensional Calibration (0–150 mm)

Verifies zero repeatability, jaw parallelism, outside diameter accuracy, and inside jaw offset against Grade 0 Gage Blocks.

📅 Calendar Interval Every 90 days

🔄 Usage Cycle Trigger Every 5,000 cycles

🌡 Ambient Temp Spec 18.0 °C – 22.0 °C

💧 Relative Humidity Spec 35% – 55% RH

⏱ Thermal Soak 60 minutes

🏛 Master Standard STD-GB-01 (Mitutoyo Grade 0 Master Gage Block Set (81-Piece))

⚠️ Pre-Calibration & Safety Instructions: Clean measuring faces and Grade 0 gage blocks with lint-free optical wipes and isopropyl alcohol. Allow 60 minutes thermal stabilization on the granite surface plate before recording readings.

Step-by-Step Procedure Checklist (5 steps)

De-burr, Clean & Thermal Soak

Clean external/internal jaws and beam slide with IPA. Place caliper and Grade 0 gage blocks on granite plate for 60 minutes.

✓ Acceptance: No burrs, smooth slider travel, 60-min soak complete

💡 Note: Never use abrasive pads on measuring faces.

Jaw Light-Gap & Parallelism Inspection

Close outside jaws gently and hold against a uniform light source to inspect for light leakage along the contact length.

✓ Acceptance: No visible light gap > 0.005 mm along jaw length

💡 Note: Excessive thumb pressure masks jaw wear.

Zero Point & Repeatability Check

Zero the digital display with jaws closed, open to 50 mm and close 5 times consecutively.

✓ Acceptance: Returns to 0.00 mm on all 5 closures

💡 Note: Record As-Found zero before pressing ZERO if offset exists.

Outside Jaw 3-Point Gage Block Verification

Measure the 25.00 mm, 75.00 mm, and 150.00 mm Grade 0 gage blocks at the center of the outside jaws.

✓ Acceptance: Within ±0.02 mm of nominal at all checkpoints

💡 Note: Keep gage block perpendicular to beam.

Apply Calibration Status Label & Seal

Affix tamper-evident calibration sticker with Certificate ID, Technician Initials, and Next Due Date.

✓ Acceptance: Label legible and signed

💡 Note: If any point fails ±0.02 mm, tag RED and quarantine immediately.

Target Measurement Checkpoints & Tolerances (4 points)

#	Checkpoint Parameter	Nominal Target	Tolerance	Acceptable Range
1	Closed Outside Jaws (Zero)	0 mm	-0.01 / +0.01 mm	-0.01 to 0.01 mm
2	Outside Jaw — 25 mm Gage Block	25 mm	-0.02 / +0.02 mm	24.98 to 25.02 mm
3	Outside Jaw — 75 mm Gage Block	75 mm	-0.02 / +0.02 mm	74.98 to 75.02 mm
4	Outside Jaw — 150 mm Gage Block	150 mm	-0.02 / +0.02 mm	149.98 to 150.02 mm

SOP-CAL-204 Torque Rev 3.1📜 ISO 6789-1:20172 tool(s) assigned

Electronic & Click Torque Wrench Verification (20%, 60%, 100% Scale)

Three-point clockwise torque verification at 20%, 60%, and 100% of maximum nominal torque capacity on the master torque transducer bench.

📅 Calendar Interval Every 60 days

🔄 Usage Cycle Trigger Every 2,500 cycles

🌡 Ambient Temp Spec 18.0 °C – 24.0 °C

💧 Relative Humidity Spec 30% – 60% RH

⏱ Thermal Soak 30 minutes

🏛 Master Standard STD-TRQ-02 (CDI Suretest 5000-ST Master Torque Transducer Bench)

⚠️ Pre-Calibration & Safety Instructions: Exercise the torque wrench 5 times at 80% full scale before taking As-Found readings. Apply force smoothly to the center of the grip handle without jerking.

Step-by-Step Procedure Checklist (5 steps)

Pre-Calibration Mechanical Inspection & Preload

Inspect square drive, ratchet pawl, and battery/display. Cycle wrench 5 times at 80 Nm on transducer bench.

✓ Acceptance: No cracked housing or ratcheting slip

💡 Note: Do not adjust setting before recording As-Found values.

Zero Master Torque Transducer (STD-TRQ-02)

Verify ambient temperature (18–24°C) and zero the CDI 5000-ST transducer in Track/Peak mode with no load applied.

✓ Acceptance: Transducer reads 0.00 Nm

💡 Note: Check that STD-TRQ-02 certification is active.

20% Scale Verification (20.00 Nm)

Set wrench to 20.00 Nm. Apply slow, steady clockwise load (1–2 sec to peak) and record peak transducer reading.

✓ Acceptance: 19.20 Nm to 20.80 Nm (±4% ISO 6789)

💡 Note: Stop pulling immediately upon click/beep.

60% & 100% Scale Verification (60.00 Nm & 100.00 Nm)

Repeat steady clockwise verification at 60.00 Nm and 100.00 Nm settings.

✓ Acceptance: 60 Nm: 57.60–62.40 Nm | 100 Nm: 96.00–104.00 Nm

💡 Note: If adjusted, re-run all 3 points for As-Left certification.

Reset Cycle Counter & Affix Tag

Return mechanical scale to minimum setting (if click-type), reset station cycle counter, and attach calibration tag.

✓ Acceptance: Stored at minimum scale setting

💡 Note: Leaving click wrenches compressed fatigues the internal spring.

Target Measurement Checkpoints & Tolerances (3 points)

#	Checkpoint Parameter	Nominal Target	Tolerance	Acceptable Range
1	Low Range (20% Scale)	20 Nm	-0.8 / +0.8 Nm	19.2 to 20.8 Nm
2	Mid Range (60% Scale)	60 Nm	-2.4 / +2.4 Nm	57.6 to 62.4 Nm
3	Full Scale (100% Scale)	100 Nm	-4 / +4 Nm	96 to 104 Nm

SOP-CAL-302 Dimensional Rev 5.0📜 ISO 3611:20232 tool(s) assigned

Outside Micrometer Optical Flat & Gage Block Calibration (0–25 mm)

High-precision verification of anvil/spindle flatness using monochromatic optical flats and lead-screw linearity using staggered gage block sizes.

📅 Calendar Interval Every 180 days

🔄 Usage Cycle Trigger Every 3,000 cycles

🌡 Ambient Temp Spec 19.0 °C – 21.0 °C

💧 Relative Humidity Spec 35% – 50% RH

⏱ Thermal Soak 120 minutes

🏛 Master Standard STD-GB-01 (Mitutoyo Grade 0 Master Gage Block Set (81-Piece))

⚠️ Pre-Calibration & Safety Instructions: Wear thermal-insulating metrology gloves when handling the micrometer frame and gage blocks. Use ratchet stop for 3 clicks on every measurement.

Step-by-Step Procedure Checklist (3 steps)

Clean Anvil/Spindle & 120-Min Thermal Soak

Draw clean bond paper between lightly closed anvil and spindle faces. Stabilize in Metrology Lab for 120 minutes.

✓ Acceptance: Mirror finish clean; lab at 20.0°C ± 1.0°C

💡 Note: Always wear metrology gloves.

Optical Flat Fringe Interference Check

Place optical flat on anvil and spindle under monochromatic helium light and count interference fringes.

✓ Acceptance: ≤ 2 red interference fringes (≤ 0.0006 mm flatness)

💡 Note: Parallelism must be within 0.002 mm.

Multi-Angle Gage Block Verification (0, 6.5, 12.5, 25 mm)

Measure Grade 0 blocks at 6.500 mm, 12.500 mm, and 25.000 mm to test spindle pitch at fractional rotations.

✓ Acceptance: All points within ±0.002 mm

💡 Note: Use 3 clicks of ratchet stop for uniform measuring force.

Target Measurement Checkpoints & Tolerances (4 points)

#	Checkpoint Parameter	Nominal Target	Tolerance	Acceptable Range
1	Anvil Contact Zero	0 mm	-0.001 / +0.001 mm	-0.001 to 0.001 mm
2	6.500 mm Fractional Rotation	6.5 mm	-0.002 / +0.002 mm	6.498 to 6.502 mm
3	12.500 mm Half-Span Block	12.5 mm	-0.002 / +0.002 mm	12.498 to 12.502 mm
4	25.000 mm Full-Span Block	25 mm	-0.002 / +0.002 mm	24.998 to 25.002 mm

SOP-CAL-405 Pressure Rev 2.4📜 ASME B40.1001 tool(s) assigned

Hydraulic Digital Pressure Gauge 4-Point Rising/Falling Calibration (0–500 PSI)

Compares manifold gauge readings against Fluke 754 / 750P06 Reference Module across 0%, 25%, 50%, and 100% span.

📅 Calendar Interval Every 120 days

🔄 Usage Cycle Trigger Every 1,500 cycles

🌡 Ambient Temp Spec 18.0 °C – 25.0 °C

💧 Relative Humidity Spec 25% – 65% RH

⏱ Thermal Soak 30 minutes

🏛 Master Standard STD-PRS-03 (Fluke 754 Documenting Process Calibrator + 750P06 Module)

⚠️ Pre-Calibration & Safety Instructions: LOTO Warning: Depressurize hydraulic line to 0 PSI and wear safety glasses before uncoupling gauge from test stand.

Step-by-Step Procedure Checklist (2 steps)

Depressurize, Isolate & Connect to Fluke 754 Manifold

Follow LOTO to isolate gauge, bleed residual hydraulic pressure, and mount on comparison test pump.

✓ Acceptance: Zero leak rate over 2 minutes at 500 PSI

💡 Note: Wear eye protection during high-pressure verification.

4-Point Rising & Falling Pressure Verification

Apply 0.0, 125.0, 250.0, and 500.0 PSI on rising and falling cycles to verify hysteresis and linearity.

✓ Acceptance: Within ±1.50 PSI (±0.3% FS) at all points

💡 Note: Wait 30 seconds at each step for adiabatic stabilization.

Target Measurement Checkpoints & Tolerances (4 points)

#	Checkpoint Parameter	Nominal Target	Tolerance	Acceptable Range
1	Ambient Vented Zero (0% FS)	0 PSI	-0.5 / +0.5 PSI	-0.5 to 0.5 PSI
2	Quarter Span (25% FS)	125 PSI	-1.5 / +1.5 PSI	123.5 to 126.5 PSI
3	Mid Span (50% FS)	250 PSI	-1.5 / +1.5 PSI	248.5 to 251.5 PSI
4	Full Scale Proof (100% FS)	500 PSI	-1.5 / +1.5 PSI	498.5 to 501.5 PSI

SOP-CAL-510 Temperature Rev 2.0📜 AMS 2750G Pyrometry1 tool(s) assigned

Curing Oven RTD & Infrared Pyrometer Dry-Block Calibration (50–250 °C)

Three-point thermal comparison in dry-well bath against NIST-traceable secondary PRT probe.

📅 Calendar Interval Every 90 days

🔄 Usage Cycle Trigger Every 1,000 cycles

🌡 Ambient Temp Spec 19.0 °C – 23.0 °C

💧 Relative Humidity Spec 30% – 55% RH

⏱ Thermal Soak 45 minutes

🏛 Master Standard STD-TMP-04 (Fluke 1524 Reference Thermometer with Secondary PRT Probe)

⚠️ Pre-Calibration & Safety Instructions: Allow dry-block well to stabilize within ±0.02 °C for 10 minutes at each temperature setpoint before logging.

Step-by-Step Procedure Checklist (2 steps)

Insert Reference PRT & Unit Under Test in Dry-Block Well

Place Fluke 5615 PRT and sensor under test into matching sleeves at full immersion depth.

✓ Acceptance: Equal immersion depth; minimal air gap

💡 Note: High temperature hazard above 100°C.

Verify Setpoints at 50.0°C, 150.0°C, and 250.0°C

Stabilize 10 minutes per setpoint and record Reference PRT vs. Tool reading.

✓ Acceptance: Within AMS 2750G tolerance at all 3 points

💡 Note: Do not quench hot probe in liquids.

Target Measurement Checkpoints & Tolerances (3 points)

#	Checkpoint Parameter	Nominal Target	Tolerance	Acceptable Range
1	Low Setpoint (50 °C)	50 °C	-0.5 / +0.5 °C	49.5 to 50.5 °C
2	Cure Soak Setpoint (150 °C)	150 °C	-0.8 / +0.8 °C	149.2 to 150.8 °C
3	High Limit Setpoint (250 °C)	250 °C	-1 / +1 °C	249 to 251 °C