Operation; Control Logic; Sequence Of Operation; Starting And Stopping The Sampler Controller - Sentry P2B-4/7 Installation, Operation & Maintenance Manual

Operation

Control Logic

The manual sampler controller included with the sampler is designed to operate the sampler . The control logic
includes:
1. Cycle time: Determines the duration between samples .
2. Sample time: Determines the duration the sample probe is extended into the process . Setting this timer determines
the sample volume collected per cycle .
3. Manual Sample (HAND): Allows the operator to immediately collect a sample .
4. Automatic Sample (AUTO): Allows the operator to initiate continuous sampling .
5. Auto light: Indicates sampler is currently sampling or is ready for a remote start signal .
6. Batch Complete light: Indicates batch counter has reached the set number .

Sequence of Operation

The sampler controller can operate in manual (HAND) or automatic (AUTO) mode .
When the selector switch is held in the HAND position:
ƒ The sampler solenoid is energized .
ƒ The sampler solenoid stays energized until the switch is released and it returns to the OFF position .
When the sampler controller is placed in AUTO mode a sample is taken immediately:
ƒ The sample timer (TDR 104) starts, the sampler solenoid is energized, the air cylinder extends the sample tube, and a
sample is taken .
ƒ When the sample timer expires, the sampler solenoid is de-energized and the air cylinder retracts the sample tube
and the cycle timer (TDR 106) is activated .
ƒ When the cycle timer expires, the sample timer resets and the sample cycle starts again . Sampling continues until
the sampler controller is turned OFF or the batch count is met .

Starting and Stopping the Sampler Controller

Before operating the sampler controller, set the timers to the desired values .
Timers
Set the sample timer (TDR 104) and cycle timer (TDR 106) by placing the DIP switches in the ON or OFF position .
ƒ The number next to each DIP switch indicates the number of seconds that switch represents .
ƒ To determine the timer setting, add the number values of the DIP switches in the ON position .
– For example, in the image below, TDR 106 is set for 1 + 4 = 5 seconds .
Sentry P2B-4/7 Controller 7