Xylem DH-21 - Manual (Page 110)

A-2 Specifications
DH-21
Environmental Restrictions
Operating Range:
0 to 40 C (nonfreezing)
Compensated Range: 0 to 40 C
Storage: -10 to 70 C
Extended Range: Consult Factory
Media Compatibility
Liquids and gases compatible with PVC, Polyethylene, Stainless Steel and Ethylene Propylene.
Pressure Port
Stainless steel screen with 149 micron filter, field replaceable.
LOGGER SPECIFICATIONS
Communications Interface
Stored data is extracted via an RS-232 or RS-485 connection at 9600 baud, 8-bit with no parity, 1 stop
bit.
Capacity
Memory:
Nonvolatile FLASH Memory, 128Kbytes, upgradable to 256Kbytes
Number of
Data Points:
43,688 Data Points typical for 128Kbytes (logging date, time, pressure,
temperature and battery voltage)
Upgradable to 256Kbytes (87,376 data points typical)
User Notes: 160 ASCII characters
Logging Modes
Types of Logging:
Time Linear: Programmable from 1 second to 24 hours
Linear : Logs on 1 second to 24 hour intervals. Logs data dependent on a change
specified by user. This mode conserves memory.
Linear Hyper: Logs on 1 second to 24 hour intervals. In this mode important events are not
likely to be missed. Data is collected at up to 256 times the normal logging rate
when a user defined rate of change is exceeded.
Linear Hyper : Logs on 1 second to 24 hour intervals. This mode minimizes memory use and
prolongs battery life by adjusting the logging rate as defined by user entered rate
of change.
Variable: Allows user to define Logarithmic / Variable logging intervals, 6 user definable
intervals. (Ideal for well testing and other applications.)
Zero Offset Command
Allows user to set offset to zero either at zero pressure or at a datum or reference point.