
Based on what I found on the web the factor is usually 385. Type 391 is available but a special order from Temp-pro. Bought one of these to connect to Omega PID. At 100 degrees Fahrenheit, there was less than 1/4 degree difference compared to a 1/10 degree certified yellow backed mercury thermometer.

β Stainless Steel L-Square, Size 3-Inch x 4-Inch, Zona 37-434
8 Review

Kapro - 353 Professional Ledge-It Try & Mitre Square - For Leveling And Measuring - Features Stainless Steel Blade, Retractable Ledge, And Etched Ruler Markings - 12 Inch
23 Review

π Johnson Level and Tool 400EM-S 12-Inch Heavy Duty Metal Combination Square for Professionals, with Inch/Metric Measurements, Silver - 1 Square
8 Review

Triangle Group TR918 225/45 R18 95V summer
61 Review