Dew Point - Transmitter - Meter - Hygrometer

Economically priced Alpha Systems dew point hygrometer designed for continuous analysis of air or gas or the regeneration of desiccant dryers. 


  • Rapid Response
  • Display in C, F Dewpoint, ppmv,ppbv & lbs/MMSCF
  • Accuracy to +/- 2 degrees C Dewpoint
  • Built in AUTO CAL procedure
  • NEMA IP66
  • metric and non metric units
  • Linear analog output 4 - 20 mA
  • Two relay alarms
  • Universal Power supply 24-230VAC
  • Traceable Calibration
  • UL 508

Dew Point
The dew point is defined as the lower temperature to which air must be cooled in order for condensation to occur. The dew point is dependent on the concentration of water vapor present, and therefore on the relative humidity.

Dewsmart Sensor
The model DS1200 is an on-line hygrometer designed to measure moisture in process gases and dry compressed air. The panel mounted display and AMT sensor are both rated for NEMA 4 service. The DS1200 with AMT ultra-high capacitance sensors provide excellent performance and accurate trace moisture measurement. The combination of advanced digital technology of the display electronics and sensor, makes this the system of choice for a wide range of applications where precise indication, control and monitoring is critical.

The model DS1200-AMT system can be factory configured to read out in °C dewpoint, °F dewpoint, ppm(v), ppb(v), g/m³ or lbs/ MMSCF. The measured value is displayed on a large 4 digit, fourteen segment LED display.

The instrument offers two fully programmable alarm relays, which can be independently set across the full operating range of the sensor. An optically isolated 4-20 ma signal, linear with the measurement units, is also provided.

The model DS1200-AMT can be supplied with one of three different sensor ranges.

The long lifetime sensor offers excellent low end sensitivity, repeatability and response speed - especially on dry down. Integrated electronics in each sensor allow calibration data to be stored within its memory, making sensors completely field interchangeable. Each sensor is calibrated to provide an accuracy of better than ±2°C dewpoint and is supplied with a certificate traceable to NIST or other standards.

The “ AUTOCAL” feature provideds for easy field verification of the system response, without the need for additional equipment.
The DS1200-AMT display can be remotely mounted over 1/2 mile (3280 feet) from the sensor, connected by
a simple twisted pair cable.

Installation using sensor holder
The drawings show the sensor mounted in a holder which is connected to the gas line to be tested. The sensor may be installed at line pressure ( fig 1.) or at atmospheric pressure ( fig 2.). We recommend installation at atmospheric pressure because the sensor is then protected from condensate in the event of a drier failure.
Sample should be taken from the upper surface of  the main line to prevent any risk of condensate reaching the sensor. Additional components may required for specific applications. Use stainless steel , nickel or copper piping wherever possible. The connections to the sample chamber are Swagelock fittings.
Sensor Dimensions
Specification of DS1200 Dewpoint Hygrometer
Model DS1200
Panel meter/system

HD -65°C to +20 °C dewpoint. (-85°F to +68 °F)
SD -100°C to +20°C dewpoint. (-148°F to +68 °F)
LD -120°C to +20°C dewpoint. (-184°F to +68 °F)

Display 4 digit 14 segment bright red LED 0.5"
Resolution 0.1 degsC, 0.1 degs F dewpoint or 0.1ppm (v)
Alarm relays 2 sets of voltage free changeover alarm contacts rated at 7A@240 VAC, 7A@30VDC
Set points adjusted from the front panel
Analog Output Isolated 4 - 20 mA, max load 800 Ohms
Power Supply

24 - 250 VAC 3.5W, 50/60Hz universal power adaptor. Or
20 - 300 VDC / 150 - 15 mA

Panel Meter Housing 1/8 Din IP66 front panel.
Cutout dimensions 92 x 45 mm
Sensor type Aluminum Oxide Ultra High Capacitance patented Alpha Systems Dewsmart.
Sensor Accuracy +/- 2 degs C dewpoint
Repeatability better than +/- 3°C dewpoint
Pressure From 0.15 PSIA (0.01 barA) to Maximum 5,075 PSIA ( 350 barA)
Sample Flow Flow independent, ideally 4 to 10 SCFH (2 to 5 LPM). Max: 50 SCFH.
Case material Stainless steel IP 65 weatherproof
Connector 8 pin
Cable 4 wire shielded up to 100 m length
Sensor Holder  
Material Stainless Steel
Connections 1/4 inch Swagelock tube fittings
Mountings 2 x M5 tapped holes in base or 
4 holes 5 mm diameter @ 42 x 35 centers in mounting bracket
Warm up time 10 seconds
Operating conditions -20 to +60 °C (-4°F to 140°F)
10 - 90 % RH non condensing
Storage temperature -20 to +70°C (-4°F to 158°F)
Electromagnetic Emission & Immunity: Complies with EN 61326
LVD 73/23/EEC: Complies with EN 61010-1
Ordering Information Price $US view shopping cart
DS1200 includes sensor, panel meter, and 6 ft cable, 2 alarm relays - 4-20 mA output From $2570 base price. order on line
dew point kit
Select Instrument Range
DS1200-AMT-XXX Range and display units
HDF -85°F to +68 °F dewpoint + $0
SDF -148°F to +68 °F dewpoint. + $300
LDF -184°F to +68 °F dewpoint. + $300
HDC -65°C to +20 °C dewpoint. + $0
SDC -100°C to +20 °C dewpoint. + $300
LDC -120°C to +20°C dewpoint. + $300
SPX 1 to 1000 PPMv + $300
MPX 0.1 to 100 PPMv + $300
LPX 0.01 to 10 PPMv + $300
PBX 1 to 1000 PPBv + $300
LB20 0.1 to 20 lb/10^6 ft^3 + $300
*CO2 For CO2 service add CO2 after range. + $0
Select Sensor Cable Length  
CAB-AMT-(XXX) Description  
006 Standard 6 foot cable with prewired NEMA 4 sensor connector. + $0
XXX Custom cut length in feet (NEMA 4 sensor connector not pre-wired) + $1.50 per foot
Select Sample Cell Type (Optional)  
SH-AMT-(X)-(X) Description  
0-0 Cell with two 1/8" NPT female threaded connection. + $240
8-8 Cell with two 1/8" tube fitings. + $275
4-4 Cell with two 1/4" tube fittings. + $275
x Explosion proof (NEMA 7/9) sensor enclosure with integral sample cell with 1/8" NPT threaded connections. + $695
Code added to the end of the instrument P/N Description  
4X Nema 4x enclosure, wall mount for DS1200 instrument. $530
HPR High pressure regulator. Stainless Steel. Max 3,000 PSIG. 1/4" FNPT connections. $595
LPR Low pressure regulator. Stainless Steel. Max 250 PSIG, 1/4 FNPT connections. $280
F Coalescing filter. Stainless Steel. Max 3,000 PSIG. 1/4" FNPT connections. $350
NV Needle valve. Stainless Steel. Max 3,000 PSIG 1/4" tube connections. $150
FI Flow Indicator. Max 100 PSIG. 1/4 FNPT connections. $380
AMT Transmitter Only
Includes 6' Coaxial Cable and NIST Traceable Calibration Certificate.
AMT Base Price $1620 Call or Email
HDF -85°F to +68 °F dewpoint + $0
SDF -148°F to +68 °F dewpoint. + $300
LDF -184°F to +68 °F dewpoint. + $300
HDC -65°C to +20 °C dewpoint. + $0
SDC -100°C to +20 °C dewpoint. + $300
LDC -120°C to +20°C dewpoint. + $300
SPX 1 to 1000 PPMv + $300
MPX 0.1 to 100 PPMv + $300
LPX 0.01 to 10 PPMv + $300
PBX 1 to 1000 PPBv + $300
LB20 0.1 to 20 lb/10^6 ft^3 + $300
*CO2 For CO2 service add CO2 after range. + $0

Topac Inc. 231 CJC Highway, Suite 103 Cohasset MA 02025 USA
Tel: 781 740 8778 Fax: 781 740 8779

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