Omega Products EWS-RH User Manual

Economical Wall-Mount
Environmental Sensors
and Transmitters

EWS Series

U Thermocouple, RTD,

or Thermistor
Sensor Models

U Connects to Computer,

Data Logger, or Industrial
Controller/Meter

OMEGA’s low-cost environmental
wall mount sensors keep your
office, computer room, or laboratory
looking great. They are compatible
with most process meters, controllers,
recorders, data loggers, and data
acquisition systems. Thermocouple,
RTD, and thermistor models come
with 1 m (40") leads. Temperature,
temperature/humidity, and pressure
units come with industry-standard,
user-selectable 4 to 20 mA or
1 to 5 Vdc output.

Specifications

Enclosure Material:

Acrylonitrile butadiene styrene
Dimensions: 45 H x 54 W x 79 mm L

(1.78 x 2.12 x 3.12")

Thermocouple Sensors

Max Temperature: 60°C (140°F)
Accuracy: ±1.1°C (1.98°F)
Sensor Types: J, K, T, E
Sensor Lead Length: 1 m (40")
Lead Material: 24 AWG, PFA coated

RTD Sensor

Max Temperature: 60°C (140°F)
Accuracy: ±1°C (1.8°F)
Sensor Type: 100 Ω Pt 0.00385
Sensor Lead Length: 1 m (40")
Lead Material: PFA insulated,

3-conductor 26 AWG stranded
nickel-plated copper

Thermistor Sensor

Max Temperature: 60°C (140°F)
Accuracy: ±0.2°C (0.36°F)
Sensor Type: OMEGA® 400 Series

2252 Ω @ 25°C

Sensor Lead Length: 1 m (40")
Lead Material: PVC insulated,

2-conductor 22 AWG stranded
nickel-plated copper

Temperature Transmitter

Range: -18 to 57°C (0 to 135°F)

Accuracy@ 25°C:

In Still Air: ±0.7°C
(±1.2°F) @ 25°C; ±1.4°C
(±2.5°F) across full range
In Moving Air: ±1.4°C
(±2.5°F) @ 25°C; ±1.7°C
(±3°F) across full range

Note: Not recommended for fast-moving-air applications.

Repeatability: ±0.3°C (±0.5°F)
Output: 4 to 20 mA or 1 to 5 Vdc

(user selectable)

Temp Time Constant (for 63.2%
Response): 9 s in moving air

(1m/s), 30 s in still air

Power: 12 to 24 Vdc
Max Loop Resistance:

Ω = (V supply – 8 V)/0.02 A

Sensor Type: Solid state

Temperature/Humidity
Transmitter

Range: 5 to 95% (non-condensing)
Accuracy@ 25°C: From 5 to 20%,

±4% RH; from 20 to 80%, ±3% RH;
from 80 to 95%, ±4% RH

Repeatability: ±1% RH; ±0.3°C (±0.5°F)
Range: -15 to 60°C (5 to 140°F)
Accuracy@ 25°C:

In Still Air: ±0.7°C (±1.2°F) @ 25°C;
±1.4°C (±2.5°F) across full range
In Moving Air: ±1.4°C (±2.5°F)

@ 25°C; ±1.7°C (±3°F) across full range
Output: 4 to 20 mA or 1 to 5 Vdc

(scaled for 0 to 100% RH)

Power: 12 to 24 Vdc
Max Loop Resistance:

Ω = (V supply – 8 V)/0.02 A

EWS-TX
shown
smaller than
actual size.

RH Time Constant: 100 s from

20 to 90%, 60 s from 90 to 20%
Sensor Type: Thin-film polymer capacitor

(see Temperature Transmitter for
temperature specifications)

Barometric Pressure Transmitter

Pressure Range: 20.8 to 32 inHg

(10.2 to 15.7 psi)

Temp Compensation: Across full range
Accuracy: ±1% of span @ 25°C (77°F)

±0.11%/°C (0.06%/°F)
Operating Temp Range:

0 to 60°C (32 to 140°F)
Output: User-selectable 4 to 20 mA,

1 to 5 Vdc

Power: 12 to 24 Vdc
Max Loop Resistance:

Ω = (V supply – 8 V)/0.02 A

Media Compatibility: Clean, dry air and
non-corrosive gases

OMEGACARESM extended

SM

warranty program is available for
models shown on this page. Ask
your sales representative for full

Extended Warranty

Program

details when placing an order.
OMEGACARE
labor and equivalent loaners.

SM

covers parts,

To Order Visit omega.com/ews_wall_mnt_all for Pricing and Details

Model No. Description

EWS-TC-(*) Thermocouple sensor

EWS-RTD RTD sensor (100 Ω Pt 0.00385)
EWS-TH 400 Series thermistor sensor
EWS-TX Temperature transmitter
EWS-RH Temperature/humidity transmitter
EWS-BP-A Barometric pressure transmitter
EWS-MB Conduit box mounting bracket/wall plate adaptor kit
PSR-24S Regulated power supply, US plug, 90 to 264 Vac input,

24 Vdc output, 400 mA, screw terminals, UL

PSR-24L Regulated power supply, US plug, 90 to 264 Vac input,
24 Vdc output, 400 mA, stripped leads, UL

PSR-24L-230 Regulated power supply, European plug, 230 Vac input,
24 Vdc output, 400 mA, stripped leads, CE

TX4-100 Shielded 4-conductor transmitter cable, 30.5 m (100')

Insert thermocouple Type J, K, T or E

*

Note: “-TC” and “-TH” models come with 1 m (40") of lead wire. For longer lead wire, add

suffix “-(#)FT” for additional cost per foot (over 3') to price. For “-RTD” models, additional cost
per foot to the price.

Example: EWS-TC-K-8FT, wall mount Type K thermocouple sensor with 8' lead wire.

Ordering Examples: EWS-TX, temperature transmitter EWS-MB, bracket/wall plate, PSR-24S,
power supply, TX4-100 transmitter cable.

OCW-3 OMEGACARESM extends standard 1-year warranty to a total of 4 years.

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