Precision Range Transmitter
The DR800 Draft Range Transmitter is designed exclusively for very low pressure measurement needs. It has a “true” full-scale range as low as ±0.25” H2O, making it ideal for air flow control applications. It can be turned down to ±0.1” H2O; higher full-scale ranges to ±100” H2O are available. The DR800 offers 0.5% accuracy and an operating temperature range of -20°F to +185°F. The total combined temperature effects are less than 3%/100°F and it also has simplified the zero and span adjustments.
The Model DR800 uses a programmable circuit board jumper in conjunction with a 20-turn potentiometer to achieve a smooth, accurate zero adjustment. Using the pot/jumper combination, ranges can be selected from –100% zero elevation to +85% zero suppression (see Fig. 1). Also, the span adjust has a HI and LO gain jumper to allow better full-scale setpoint resolution. This achieves more turns from the potentiometer over a smaller percentage of the span and zero adjust range making critical setpoint calibrations easier and less time consuming.
The DR800 has been designed for easy field repair if required. All the electronics are housed in the NEMA housing on top of the transducer and joined to the transducer through a single plug in the neck of the transmitter. The entire electronics housing can be removed and replaced in a matter of minutes without removing the transducer from its mounting. The electronic circuit board is also field repairable; no special tools are required.
- General Specifications
|Pressure Media||Media compatible with 410 SS|
|Power Supply||Two-wire configuration, 12-45 Vdc; external supply required.|
|Indication||Optional 3½ digit liquid crystal display (LCD) independently selectable for readout in percent of full-scale or mA units.|
|Zero Adjust||Continuously adjustable 20-turn external zero pot. Works in combination with circuit board jumper to provide a zero setpoint from –100% to +85% of full-scale|
|Span Adjust||Continuously adjustable 20-turn external span pot provides turn-down ratios up to 2.5:1. Works in combination with circuit board jumper for bipolar applications|
|Temperature effects||3%/100°F combined zero and span, -20°F to +185°F|
|Humidity||0-100% relative humidity|
|Over-pressure Limits||±5 psi (with less than 5% FS Zero Shift)|
|Max. line pressure||100 psi 10” and below; 2000 psi above 10”.|
|Line Pressure Coefficient||10” H2O FS and below, 1% FS or less per 100 psi; above 10” H2O FS, 1% FS or less per 400 psi (typical).|
|Accuracy||0.5% or better, including non-linearity, hysteresis, non-repeatability, and dead band.|
|Signal Output||4-20 A (true two-wire system|
|Pressure Connections||Industry standard (¼ ” NPT ports on 2 ” centers) machined for pressure adapters. Optional adapters provide ½ ” NPT ports on adjustable centers of 2”, 2 ”, or 2¼ ”|
|Mounting||Bracket available for 2” pipe|
|Electrical Enclosure||NEMA 4 with Neoprene gasket and threaded covers|
|Corrosion Capability||Media compatible with 410 SST, Inconel, 316 SST and selected O-ring material|
The DR800 has been designed for easy field repair
if required. All the electronics are housed in the
NEMA housing on top of the transducer and joined
to the transducer through a single plug in the neck of
the transmitter. The entire electronics housing can
be removed and replaced in a matter of minutes
without removing the transducer from its mounting.
The electronic circuit board is also field repairable;
no special tools are required.