Technical and Math Character Entry

Some technical "alt-character" shortcuts I find useful are below. I've memorized some favorites like • and Ω. List bullet symbol entry is particularly useful for lists in software that doesn't traditionally support them, such as within Excel cells or in basic text editors.

Another quick tip is to use "ALT =" in most Microsoft products (Word, OneNote) to quickly enter the "formula-entry" mode.

In this mode, most special characters can be entered using LaTeX syntax. Here's a decent cheat sheet for LaTeX codes for math symbols.

HOW TO:
Enter a character by holding "ALT" key and typing out the numeric (note leading zeros) on the keyboard Numpad.

Some alternative means for character entry:

• Copy-paste the characters from this webpage
• Windows "Character Map" program (on Windows 7+ search start-menu for Character Map)
• In many Microsoft products (Word, Outlook), Alt-"=" (no quotes) will start the equation editor
• Google-search a description of the character you want, copy and paste from search results

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MY FAVORITES:

• | Alt-0149 | List Bullet

Ω | Alt-234 | Omega (uppercase) (Ohms)

σ | Alt-229 | Sigma (lowercase) (standard deviation)

µ | Alt-230 | Mu (lowercase) (mean)

± | Alt-0177 | Plus/Minus (bilateral tolerancing, uncertainty)

≈ | Alt-247 | Approximately equal to

° | Alt-0176 | Degrees

GENERAL

• | Alt-0149 | List Bullet

§ | Alt-0167 | Section symbol

↑ | Alt-24 | Up Arrow

↓ | Alt-25 | Down Arrow

→ | Alt-26 | Right Arrow

← | Alt-27 | Left Arrow

MATH SYMBOLS

± | Alt-0177 | Plus/Minus

÷ | Alt-0247 | Division

° | Alt-0176 | Degrees

≥ | Alt-242 | Greater than or equal to

≤ | Alt-243 | Less than or equal to

≈ | Alt-247 | Approximately equal to

× | Alt-0215 | Multiplication (alternate)

¬ | Alt-0172 | Boolean Algebra “Not”

√ | Alt-251 | Square Root

² | Alt-0178 | Squared

³ | Alt-0179 | Cubed

┴ | Alt-193 | Perpendicular

∩ | Alt-239 | Intersection

GREEK LETTERS

α | Alt-224 | Alpha (lowercase)

ß | Alt-225 | Beta (lowercase)

Γ | Alt-226 | Gamma (lowercase)

π | Alt-227 | Pi (lowercase)

Σ | Alt-228 | Sigma (uppercase)

σ | Alt-229 | Sigma (lowercase)

µ | Alt-230 | Mu (lowercase)

τ | Alt-231 | Tau (lowercase)

Φ | Alt-232 | Phi (uppercase)

Θ | Alt-233 | Theta (uppercase)

Ω | Alt-234 | Omega (uppercase)

δ | Alt-235 | Delta (lowercase)

φ | Alt-237 | Phi (lowercase)

ε | Alt-238 | Epsilon (lowercase)
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ASSOCIATED LINKS
ASCII
Unicode
Greek Letters used in Math, Science, & Engineering

Standards and Regulations Quick Reference

General Electrical Standards:

• ANSI C84.1 - American National Standard for Electric Power Systems and Equipment - Voltage Ratings (60 Hertz)
• Voltage Input Specifications for American supply mains operated equipment. A nice practical overview is provided by PowerQualityWorld
• NFPA 70 - National Electric Code (US)
• Comprehensive American electric code for building wiring
• CAN/CSA C22.1-12 - Canadian Electrical Code
• ANSI/NEMA WD 6 - Wiring Devices—Dimensional Specifications
• Mechanical specifications for NEMA (home outlet) jacks and plugs
• IEEE 1149.1 - Test Access Port and Boundary-Scan Architecture 
• JTAG standard
• IEC 60050 - International Electrotechnical Vocabulary
• Online searchable technical glossary with traceable definitions
• UL 1310 - Class 2 Power Units
• Safety standard for "Class 2" (i.e. doubly insulated with no safety/chassis grounding) power supplies
• IEEE 315 - Graphic Symbols for Electrical and Electronics Diagrams (Including Reference Designation Letters)

Printed Circuit Design:

• IPC Standards Tree (PCB and Flex Circuit design/manufacturing/inspection standards)
• Printed Circuit Design:
• IPC 2221 - Generic Standard for Printed Circuit Design
• IPC 7351 - Generic Requirements for Surface Mount Design (Land Patterns)
• Printed Circuit Manufacturing/Performance
• IPC 6012 - Qualification and Performance Specification for Rigid Printed Boards
• MIL-PRF-31032 - General Performance Specification for Printed Circuit Board/Printed Wiring Board 
• Printed Circuit Inspection (Bare Board)
• IPC-A-600 - Acceptability of Printed Boards
• Assembly/Soldering
• J-STD-001 - Requirements for Soldered Electrical and Electronic Assemblies
• Assembly Inspection
• IPC-A-610 - Acceptability of Electronics Assemblies
• Slash sheets exist for general specifications for laminates, copper foil, etc - see the standards tree link. Printed circuit drawing may define materials by specifying the IPC slash sheet requirements.

General Product Standards:

• IEC 60529 - Degrees of protection provided by enclosures (IP Code)
• Standard for degrees of protection from dust and fluid ingress
• UL 94 - Tests for Flammability of Plastic Materials for Parts in Devices and Appliances
• Standard for plastic material flammability ratings (self-extinguishing properties)
• UL 746A - Polymeric Materials - Short Term Property Evaluations (Electrical Ignition)
• Standard for plastic material flammability ratings (electrical ignition properties)
• ISO 9001 - Quality management systems - Requirements
• General standard for enterprise quality management systems
• ISO 7000 - Graphical symbols for use on equipment -- Registered symbols
• International standard for symbol graphics
• ISO 8601 - Data elements and interchange formats – Information interchange – Representation of dates and times
• International standard for representing dates and times
• ASME Y14 - Engineering Drawings
• Has many sub-parts/sub-standards for most aspects of technical drawings
• ASME Y14.44 covers schematic reference designators

Military & US Government Standards:

• Many defense and government standards are freely available at ASSIST
• MIL spec standard microcircuit drawings (SMD) cross-reference available from DLA
• MIL specs for parts also available from DLA
• AS9100 - Quality Management Systems

Medical Device Standards:
Electrical Safety

• IEC 60601-1 - Medical electrical equipment - Part 1: General requirements for basic safety and essential performance
• International standard for medical device safety. Many countries have their own nationalized version, e.g. AAMI/ANSI 60601-1 (for compliance with US electrical code). Has multiple associated collateral standards (sub-parts). 60601-1 is not technically a prerequisite for 510(k) clearance but in practice is near-necessity to help demonstrate electrical and use safety.  
• IEC 60601-1-2 - Medical electrical equipment - Part 1-2: General requirements for basic safety and essential performance - Collateral standard: Electromagnetic compatibility - Requirements and tests
• 47 CFR §15 - Radio Frequency Devices
• FCC regulations covering intentional and unintentional EM radiators
• FDA Recognized Consensus Standards are searchable from their website

Quality Systems and Risk Management

• ISO 13485 - Medical devices - Quality management systems - Requirements for regulatory purposes
• Similar to the American FDA quality system regulations 21 CFR §820
• ISO 14971 - Medical devices - Application of risk management to medical devices
• Risk = Probability of Harm for a given hazardous situation (P2) x Probability of Occurrence of given hazardous situation (P1)

Human Factors and Usability

• AAMI HE75 - Human factors engineering - Design of medical devices
• Comprehensive human factors standard for medical devices
• IEC 62366 - Medical devices - Application of usability engineering to medical devices

Labelling

• ISO 15223-1 - Medical devices. Symbols to be used with medical device labels, labelling and information to be supplied. General requirements
• MIL-STD-130

Systems Engineering:

• ISO/IEC 15288 - Systems and software engineering - System life cycle processes
• High-level standard for a complete system lifecycle
• ISO/IEC 19760 - A guide for the application of ISO/IEC 15288 (System life cycle processes)
• IEEE 1220 - IEEE Standard for Application and Management of the Systems Engineering Process
• A much more specific example of one way to implement IEC 15288
• ISO/IEC/IEEE 42010 - Systems and software engineering. Architecture description
• ISO 9241-210 - Ergonomics of human-system interaction -- Part 210: Human-centred design for interactive systems
• IEC 15026 - Assurance Cases

Illumination Engineering:

• IES HB-10 - The IES Lighting Handbook
• Comprehensive guide to lighting engineering

Regulations:

General

• 29 CFR §1910.399 - Inspection by a NRTL - see Certified and Acceptable
• This regulation effectively requires NRTL safety marking for electronic installations in a workplace
• 49 CFR §173.185 - LITHIUM CELLS AND BATTERIES
• Hazardous materials regulation concerning the transportation of lithium cells and batteries (& products containing them)
• Directive 2011/65/EU - (RoHS) restriction of the use of certain hazardous substances in electrical and electronic equipment
• Restriction of hazardous materials in electronics (e.g. lead-free)
• Directive 2006/121/EC - Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH)
• Further restrictions of hazardous materials in electronics

Packaging and Transportation

• NMF-100 - National Motor Freight Classification
• IATA Lithium-Ion Packaging Instructions 965-970
• Packing and labeling instructions for lithium-ion batteries

Medical Devices
United States:

• 21 CFR §820 - Quality System Regulation
• 21 CFR §801 - Labeling
• 21 CFR §807 - Premarket Notification
• 21 CFR §803 - Medical Device Reporting

Canada:

• SOR/98-282 - Medical Device Regulations

Europe:

• Directive 93/42/EEC