manufacturingpure carbon is deposited on ceramic

Question

MANUFACTURING:

Pure carbon is deposited on ceramic substrate by thermal decomposition of hydrocarbon at 1000⁰C. The sheet resistance of film is controlled by controlling the thickness of the carbon film.

SPECIFICATIONS:

Range of values                                                           1 ohm to 10⁷ ohms

Temperature coefficient of resistance                              -1000pm/⁰C

Stability                                                                        < 3%

Tolerance                                                                     > 2%

Working voltage                                                            500 volts

Working temperature                                                     -40 to 120⁰C

APPLICATIONS: These resistors are used in measuring instruments where close tolerances are required. These resistors have better stability compared to carbon composition resistors. Voltage coefficient is small. Temperature coefficient is negative. For small value, size of carbon composition resistor. These resistors have no ability to withstand electrical overloads.