AEM 30-5142 Analog H2O Flow Gauge - Manual (Page 4)

Page 4
Status Lights
The AEM Flow Gauge has two status lights (see Figure 4) that indicate when a high
flow condition exists. The right status light flashes once and then repeats if flow is 1250
cc/min or more. This can be indicative of either a controlled flow rate that is beyond the
range of the gauge or a slight leak in the system. Both status lights flash four times and
then repeat if flow is 2000 cc/min or more. This can be indicative of an uncontrolled
open line condition, such as a major leak or broken connection.
Analog Output
The analog output from the AEM Water/Methanol Injection Flow gauge is a linear dc
voltage signal that varies from 0.5 vdc at 0 cc/min flow to 4.5 vdc at 1000 cc/min
flow. The signal is used for sending information to a data logger or an engine
management system like the AEM EMS or F/IC. The transfer functions for the analog
output are listed below in cc/min and gal/hr.
Flow (cc/min) = 250 * Voltage – 125
For example, if the output voltage is 2.5 volts, the flow rate is 500 cc/min.
250 * 2.50 – 125 = 500 cc/min
Flow (gal/hr) = 3.96 * Voltage – 1.98
For example, if the output voltage is 2.5 volts, the flow rate is 7.93 gal/hr.
3.96 * Voltage – 1.98 = 7.93 gal/hr
A list of output voltages and corresponding flow rates is shown below in Table 1.
NOTE: The two overflow conditions mentioned above in Status Lights have two
specific voltage outputs as listed below in bold.
Figure 4. Illuminated Status Lights
Left
Status
Light Right
Status
Light