Tom Riddle

Precision Instrument Restorer · Toronto, ON
Manual No. JD-170 Revision C · Issued 2026
riddle.bench@example.com
(416) 555-0192 · example.com/riddle
Operating Instructions Read all sections before placing this candidate in service.
1.0

General Description

p. 1

1.1I restore and calibrate mechanical measuring instruments: chronometers, barographs, theodolites, and laboratory balances. Over 14 years I have returned roughly 2,300 instruments to service, most of them between 60 and 120 years old.

1.2I hold calibration records to a repeatable standard of ±0.02 mm on linear instruments and 4 seconds per day on marine chronometers. I also keep a card index of every screw I have ever lost, which currently lists 3.

2.0

Identification of Parts

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1
Escapement work
2
Calibration record
3
Client handover
4
Archive index
Riddle · Model 1982 · Serial TOR-0714
Fig. 1 · The candidate, shown with principal working faculties
  • (1) Escapement work: fine motor repair, hairsprings to 0.03 mm wire.
  • (2) Calibration record: traceable logs kept for every unit since 2012.
  • (3) Client handover: written care instructions with each return.
  • (4) Archive index: 4,100 parts cataloged by maker and pitch.
Callout leaders omitted at this width. See key above.
CAUTION
Do not assign this unit to work that forbids disassembly. The candidate will open the case. This behaviour is by design and cannot be disabled.
3.0

Operation · Service History

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3.1 · Proprietor & Head Restorer 2017 – Present
Riddle Instrument Works · Toronto, ON
  1. Completed 180 to 210 restorations per year across chronometers, transits, and analytical balances, with a 3.1% warranty return rate.
  2. Built a two-person apprentice bench; both apprentices now pass the shop's blind calibration test within ±0.05 mm.
  3. Hold service contracts with 4 museums and 2 university physics departments, worth CAD 96,000 annually.
3.2 · Senior Technician, Horology 2013 – 2017
Dominion Timeworks Ltd. · Toronto, ON
  1. Serviced 420 marine and pocket chronometers; brought average daily rate error from 11 s to under 4 s across the fleet.
  2. Wrote the shop's 60-page overhaul procedure, still in use and now on revision F.
3.3 · Bench Technician 2011 – 2013
Lakeshore Survey Supply · Mississauga, ON
  1. Adjusted and re-collimated 300+ theodolites and levels for survey crews, with 48-hour standard turnaround.
  2. Cut repeat repairs 22% after introducing a pre-shipment vibration check.
CAUTION
Rush jobs void the accuracy figures quoted in Section 1.2. Allow full curing time for shellac and full settling time for hairsprings.
4.0

Maintenance Schedule · Ongoing Development

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Interval Procedure Remarks
Weekly Review 2 to 3 journal articles on metrology or conservation practice Notes filed in the shop reference binder
Quarterly Verify shop reference standards against a lab in Ottawa Gauge blocks and master level, certificates on file
Annually Attend one conservation conference; deliver a talk in alternate years Last talk: cleaning lacquered brass without dial loss, 2025
As required Train apprentices on newly acquired instrument types Most recent: aneroid barograph linkages, spring 2026
5.0

Specifications

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TrainingDip. Horology, Georgian Trades Institute, 2011
CertificationCIMTA Level III bench certification, 2016
Linear accuracy±0.02 mm, repeatable
Chronometer rate≤ 4 s/day after overhaul
MachiningWatchmaker's lathe, wheel cutting, staff turning
FinishingBluing, gilding repair, lacquer conservation
DocumentationCondition reports, photo logs, care sheets
LanguagesEnglish; French (working, for Quebec archives)