Most Frequently Asked Questions
Q1.	What's the difference between capacitive discharge ignition and inductive ignition systems?
Q2.	When selecting a pickup, how do I determine diametral pitch?
Q3.	How can I maximize the output voltage of a passive magnetic pickup?
Q4.	Does gear tooth size matter when choosing a magnetic pickup?
Q5.	Where should I measure discharge temperature?
Q6.	What is the best way to measure temperatures for reciprocating analysis?
Q7.	Where should I measure suction temperature?
Q8.	What is gate time?
Q9.	How do I calculate gate time?
Q10.	What is a powered pickup?
Q11.	What's the difference between intrinsically-safe and explosion-proof?
Q12.	What is a pole piece?

Q.	What's the difference between capacitive discharge ignition and inductive ignition systems?
A.	Inductive ignition systems have a longer, variable spark duration. Inductive ignition systems are better suited for lean burn engines.
Q.	When selecting a pickup, how do I determine diametral pitch?
A.	Divide the number of teeth on the gear by the diameter of the gear in inches.
Q.	How can I maximize the output voltage of a passive magnetic pickup?
A.	If you know that your particular gear and pickup will not provide an adequate input signal to operate a meter or a speed switch at the slowest speed of interest, you can: accept a higher minimum speed use a different gear (one with fewer teeth or a larger diameter) use an externally-powered device instead of a signal-powered unit change to a different passive pickup that provides better output for your application
Q.	Does gear tooth size matter when choosing a magnetic pickup?
A.	Yes. For maximum output and a sinusoidal waveform: The dimension of the tooth top surface should be equal to or greater than the pole piece diameter. Tooth height should be equal to or greater than the space between the teeth. The space between teeth should be approximately 3 times pole piece diameter. The air gap pole piece clearance)should be as small as possible 0.005" typically). Gear width should be equal to or greater than pole piece diameter.
Q.	Where should I measure discharge temperature?
A.	Measure discharge temperatures as close to the cylinder's discharge outlet as possible.
Q.	What is the best way to measure temperatures for reciprocating analysis?
A.	The three most common ways of recording nozzle temperatures are: thermal-well readings gauge readings infra-red measurement Temperature readings taken from a thermal well are the most accurate. Gauge readings, providing the gauges are properly calibrated, are more accurate than infra-red measurements. If infra-red measurement is your only option, you can improve the reliability by taking data from a smooth surface that is painted flat black.
Q.	Where should I measure suction temperature?
A.	We recommend measuring the suction temperature at the bottle inlet to provide a consistent theoretical discharge temperature value -- one that does not deviate when there are problems with the cylinder.
Q.	What is gate time?
A.	For a digital meter to accurately display an RPM, it must count the input pulses from a pickup (speed sensor) or other frequency source - over a specific time span. That time span is known as gate time. In a sense, the meter's circuitry opens an electronic gate for the incoming pulses, counts these pulses, and then - when the calibrated gate time runs out - closes the gate. Circuitry then calculates the RPM and sends the equivalent RPM value to the LCD or LED. The process is repeated as frequently as the gate time value.
Q.	How do I calculate gate time?
A.	Gate time can be calculated by two methods: gate time = 60 ÷ (number of teeth or gear discontinuities) gate time = (maximum RPM) ÷ (equivalent frequency in Hz at that RPM)
Q.	What is a powered pickup?
A.	Powered Pickups are DC powered, providing a constant amplitude output—roughly equal to the DC input—independent of gear or shaft speed. They still must sense a ferrous material, but can perform at zero or near zero speed, providing a usable signal when a passive pickup can’t. NOTE: As a result of the power input, they cannot be classified as intrinsically safe.
Q.	What's the difference between intrinsically-safe and explosion-proof?
A.	Intrinsically-safe products mean that regardless of a circuit's condition, power levels will not be of sufficient magnitude to ignite a specific hazardous mixture. Explosion-proof products are surrounded by an enclosure that can withstand the pressure of a mixture exploding inside the enclosure and prevents propagation of the explosion to the surrounding atmosphere.
Q.	What is a pole piece?
A.	The pole piece is a part of a speed sensor. It IS a cylindrical permanent magnet behind a soft iron rod (the actual pole piece) wound with fine magnet wire. The pole piece may protrude from the pickup body, or it may be “blind end,” where the tip of the pickup is behind a solid housing front because the pickup body is one piece.