Analytical Technology A15 Especificaciones descargar pdf (Pagina 28)

ATI A15/76 Turbidity Monitor Part 6 – Operation

O&M Manual

Rev-H (8/11)

The alarm relay will always activate if either a high or low conductivity condition exists. The

setpoints for this alarm are programmable. If an alarm condition is detected, the relay will activate and the

LCD display will flash "ALARM: MEASURE”. The default values are 0 for low alarm and display range full

scale for high alarm.

To program the Alarm Relay for different low and high setpoints, proceed as follows:

1. Press the MODE key until the display shows AL at the left side. The numbers shown to the right

of AL are the current set points for that relay. Note that there are two of them. This relay will

activate if the pH concentration goes below the low setpoint or above the high setpoint.

2. Press the CAL key and the display will read "CAL AL L: XXX". Use the UP and DOWN keys to

adjust the X.XX value to the desired low alarm setpoint. Then press ENTER.

3. The display will now read "CAL AL H: XXX". Again, use the UP and DOWN keys to select the

high setpoint, and then press ENTER.

4. The display will now read "CAL AL D: 0.0s". D represents the alarm delay. Use the UP or DOWN

keys to set the alarm delay value between zero and 25 seconds. Then press ENTER and the

display will return to the starting point for this routine.

Alarm C will also activate if certain sensor problems exist. The conditions that will activate this

alarm are sensor fouling (indicated by “ALARM: FOULING”), high ambient light conditions (indicated by

“ALARM: EXT. LIGHT”), and loss of water in the flowcell (indicated by “ALARM: DRY CELL”. All of these

conditions will cause the display to flash when they occur.

Analog Output Adjustment

The 4-20 mA output from the A15/76 tracks the display value very closely. However, occasionally

the output will be connected to another device and the value shown on the remote display, recorder, or

computer does not exactly match the value on the turbidity unit. This difference may be due to small

errors in D/A conversion in both the turbidimeter and the receiving unit. It is possible to make slight

adjustments in the analog output to bring remote display values into agreement with the A15/76 display if

desired. Follow the procedure below:

1. Press the MODE key until the display D8 is shown (01 X.X mA/X.XXX NTU). This display show

the current value of the 4-20 mA output and the corresponding turbidity value.

2. Press the CAL key and the display will change to “ADJ 01: 0.00 mA”.

3. Press the CAL key again and the display will change to “CAL ADJ: 0.00 mA”.

4. Use the UP or DOWN keys to change the output in small increments either up or down to force

the output either higher or lower as needed. Then press ENTER to store the offset and see if the

remote device is not in agreement. Repeat the process if necessary.

1 2 ... 23 24 25 26 27 28 29 30 31 32

Sin comentarios

Analytical Technology A15 Especificaciones Pagina 28