Emerson Rosemount 644h, Reference Manual

Page: 51 / 78

Reference Manual
00809-0100-4728, Rev HA
December 2002
Models 644H and 644R
www.rosemount.com
Appendix A Specifications and
Reference Data
Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . page A-1
Dimensional Drawings . . . . . . . . . . . . . . . . . . . . . . . . . . . . page A-7
Ordering Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . page A-9
Stainless Steel Housing . . . . . . . . . . . . . . . . . . . . . . . . . . . page A-12
SPECIFICATIONS
Functional
Inputs
User-selectable; sensor terminals rated to 42.4 V dc. See “Accuracy” on
page A-5 for sensor options.
Output
2-wire 4–20 mA, linear with temperature or input; digital output signal
superimposed on 4–20 mA signal, available for a HART communicator or
control system interface
Isolation
Input/output isolation tested to 500 V ac rms (707 V dc) at 50/60 Hz
Local Display
The optional five-digit integral LCD Display includes a floating or fixed decimal
point. It can also display engineering units (°F, °C, °R, K,
Ω
, and millivolts),
milliampere, and percent of span. The display can be configured to alternate
between selected display options. Display settings are preconfigured at the
factory according to the standard transmitter configuration. They can be
reconfigured in the field using a HART Communicator.
Power Supply
An external power supply is required. The transmitter operates on 12.0 to
42.4 V dc transmitter terminal voltage with load resistance between 250 and
1100 ohms. A minimum of 17.75 V dc power supply is required with a load of
250 ohms. Transmitter power terminals are rated to 42.4 V dc. A HART
Communicator requires a loop resistance between 250 – 1100 ohms. Do not
communicate when power is below 12 V dc at the transmitter terminals.
Humidity Limits
0–99% relative humidity