AMC 1ACOs, Instructions Manual, Page: 28 / 33

AMC-1ACOs One Channel CO Monitor with DSI
24
EXAMPLE 1: To set an ALARM threshold of 100 PPM for a sensor (DSI) calibrated to 20 mA
for a concentration of 100 PPM;

C
alarm
: 100 PPM

C
full scale
: 100 PPM

I
Range
: 20 mA – 4 mA = 16 mA

V
alarm
= ((( 100 PPM / 100 PPM) * 16 mA) + 4 mA) * 250 * 0.4
= 2.0V

For sensor 1, RV6 would be adjusted so that 2.0V is measured at TP6.
EXAMPLE 2: Using the same sensor (DSI) as example 1, set a WARNING threshold of 25
PPM;

C
alarm
: 25 PPM

C
full scale
: 100 PPM

I
Range
: 20 mA – 4 mA = 16 mA

V
alarm
= (((
25 PPM
/ 100 PPM) * 16 mA) + 4 mA) * 250 * 0.4
= 0.8V

For sensor 1, RV5 would be adjusted so that 0.8V is measured at TP5.
5.2.2 AMC-DSI CALIBRATION
Every AMC-DSI Sensor is factory calibrated, so each unit should be ready for operation after
installation and a 30 minute stabilization time.
Calibration is recommended two times per year and all peripherals and/or relays should be
checked twice a year.
Caution:
- Only qualified personnel should perform the actual calibration.
- Users new to gas calibration are advised to consult with Armstrong Monitoring
The Armstrong Monitoring Corporation offers the following plans:
1. On site installation and calibration by Armstrong Monitoring
2. On site calibration by Armstrong Monitoring
3. Training by Armstrong Monitoring
4. Extended warranty calibration program
5. EZ Cal Sensor Replacement Program
Table 9 details the function of the test points. Refer to Figure 10 for DSI Layout.