SATO KEIRYOKI SK-M350-TRH-I User manual

Instruction Manual
Temperature/Humidity Indicator
Model SK-M350-TRH-I
No. 3 Nishi-Fukudacho, Kanda, Chiyodaku, Tokyo 101-0037 Japan
URL: http://www.sksato.co.jp/english/

1
Introduction
Thank you for purchasing the Temperature/Humidity Indicator, SK-M350-TRH-I.
-This is an indicator which displays the temperature and humidity by inputting a direct current 4 to 20mA.
SK-M350-TRH-I can be connected to a 4 to 20 mA output device or our temperature/humidity
transmitter model SK-RHC-I. Do not use this instrument for any other purposes
- Read this instruction manual thoroughly before use and keep it in a safe place for future references.
Warning DANGER
RISK OF EXPLOSION
- These instruments are not explosion-proof. Never use them in environment with flammable gases.
- For any inquiries, contact the store where you bought the instrument or our service network.
Cautions
■Please follow the instructions below for proper usage of the product.
- Never disassemble or modify the instrument. Doing so may cause malfunctions.
- These are precision instruments. Be careful not to drop, vibrate or give an impact to them
- Avoid using the instruments in a place exposed to direct sunlight or near a heat source.
Doing so may not just compromise the measurements but cause failures as well.
- Avoid using the instrument in dusty environment or salty air. Dust and dirt on the power plug may
cause fire.
- This instrument is not waterproof. Never let it wet.
- Do not use it in places in effects with condensing, rain, water drops or steam.
- If this instrument is used in an environment where electrical noise is generated, the display may
become unstable and the measurement error may increase.
- Refer to the 'Installation Method' section of this manual when installing the instrument and be careful
not to drop.
- Remove all electrical wirings before moving the instrument. Fail to do so may cause dropping of the
instrument.
- Make sure to select a proper type of adaptor in accordance with related standards and product
specifications when not using the accessory device that comes with the instrument.
The standards and specifications are stated in the 'AC adaptor' section of this manual.
■Please follow the instructions below to avoid electric shocks.
- No power switch is available for this instrument. Therefore the instrument becomes its operation
state when connected to a power source.
- Connect to a power source only after correct wiring is complete.
- Do not touch the terminals while power is being supplied.
- Do not wire the instrument in places with heavy humidity or water splash nor with wet hands.
- Make sure to put the terminal cover on during usage time in prevent from dust or an electric shock.
■Please contact the distributor where the purchase was made or our service network for any repair or
calibration of the instrument.

2
Overview
This instrument is an indicator which displays the temperature and humidity by inputting a direct current
ranging from 4 to 20 mA. This instrument can be connected to a 4 to 20 mA output device or our
temperature/humidity transmitter Model SK-RHC-I (4 to 20 mA).
Features
- Easy to read LED display with the character height of approx. 57mm
Incorporating the red LED with its character height of approx. 57mm makes the displayed values well
visible from far distance.
- Free angle fixture stand
This enables for the user to set the display at any desired angle.
- Alarm function for upper and lower limits is available for option at the time of purchase order.
A buzzer or a rotating warning light can be attached as an alarm device.

3
Names of components
(1) Display (red LED) : character height approx. 57mm
(2) Input terminal board
(3) DC jack : AC adaptor connection port
(4) Fixture stand : Plate thickness t=3.2mm, 4 holes for fixture
(5) Knob screw
(6) Cover
(7) Cable passage
(8) AC adaptor outlet
(9) Cover fixture screw : (6 holes)
(10) Alarm setting : optional
Front view
Side view
Bottom view
Rear view (with cover)
Rear view (without cover)
Standard instrument
Instrument with alarm (optional)

4
Wiring method
Cautions
- Connect to a power source only after completing the wiring.
- Please be careful not to confuse the wiring. Incorrect wiring may result in instrument failure.
- Do not wire the instrument in places with heavy humidity or water splash nor with wet hands.
- When wiring the terminal block, tighten the screws securely without a slack.
- Do not use unconnected terminals for other application such as transmission.
- In using crimp terminals, take the necessary insulation distance by an insulation tube or the kind to
avoid exposure of wires so that a electric shock or short circuit may be prevented.
- Please use the input load within the standard specifications.
- Refer to the 'Installation Method' section of this manual when installing the instrument and be careful
not to drop.
- Remove all electrical wirings before moving the instrument. Fail to do so may cause dropping of the
instrument.
- Make sure to put the terminal cover on during usage time in prevent from dust or a electric shock.
- Please use the cable with proper diameter.
- It is recommended to use a crimp terminal for wiring. Please tighten the wires securely without a slack.
- A 4 to 20 mA output device or our temperature/humidity transmitter, model SK-RHC-I, is not included
as a part of the instrument.
- The connection between each input device and the indicator is electric current connection. Therefore
in general, data can be transmitted long distance, however error may occur depending on the
connection location. Please check thoroughly environmental conditions such as the electrical noise
before wiring.
- Do not touch the electrical board and electronic components in the device.
1. Applicable cable
Diameter of applicable cable : 0.75sp (AWG18) ~ 0.34sq (AWG22)
Size of terminal screw : M3
Installation torque : 0.5N/m
* Tighten the screws with a screwdriver bit and torque that matches the screw size.

5
2. Wiring method
(1) Loosen the six screws at the rear side of the instrument and remove the cover.
* Do not loosen or re-tighten the screws other than those six screws.
(2) Insert the cable through from the outside of the cable wiring port on the cover and wire to
the terminal block as shown in the drawing below.
* Cut an opening to the film covering the cable wire port
with a cutting knife.
* Please note the direction of the cover
○ Wiring diagram
<with the cover>
<without the cover>
Cover fixture screws (size: M3)
Cover fixture screws (size: M3)
terminal block
○ Terminal description
Terminal
name
Description
T+
Temperature current input + Terminal
T-
Temperature current input - Terminal
H+
Humidity current input + Terminal
H-
Humidity current input - Terminal
Both ends are for terminal block fixture screws.
Do not loosen the screws.
Temperature
Humidity

6
○ Connecting with a Temperature/Humidity transmitter, model SK-RHC-I
Check the wiring diagram of the terminal block and wire correctly.
Terminal name
Description
T+
Temperature current input + Terminal
T-
Temperature current input - Terminal
H+
Humidity current input + Terminal
H-
Humidity current input - Terminal
*Note: The instrument is not designed to supply power to the temperature/humidity transmitter, model
SK-RHC-I. Please have another power source for SK-RHC-I for power supply. Please refer to the
instruction manual that comes with SK-RHC-I for power supply specification.
(3) Fix the cover to the instrument with screws.
* Please use the M3 screws that comes with the instrument for fixture.
* Make sure there is no wobble of the cover.
Both ends are for terminal block fixture screws. Do not loosen the screws.
Temperature
Humidity

7
Installation method
Cautions
- Be careful not to let the instrument fall when using in desktop.
- Use screws such as concrete screws in 4 holes on the fixture stand for secure fixture.
- Concrete screws are not supplied with the instrument.
- The weight of the instrument is approximately 3.8 kg. When installing, make sure to select appropriate
screws after checking installation conditions such as strength.
1. Installation location
Do not install the instrument on a rooftop.
Avoid following locations for installation:
- Places with flammable gas, explosive gas and corrosive gas such as SO2and H2S
- Places where the ambient temperature go beyond 0 to 50℃(humidity of less than 85%rh)
- Places of the impact of electrical noise and radio waves
- Places in effects with condensing, rain, water drops or steam
2. Installation method
(1) Fix the fixture stand securely to a desired installation location.
* Be careful not to let the instrument fall when using in desktop.
* Use screws such as concrete screws in 4 holes on the fixture stand for secure fixture.
○ An example of installation

8
○ Dimensions of the fixture stand (bottom view)
* Plate thickness t=3.2mm
(2)Loosen the knob screws at both sides of the fixture stand and adjust the indicator in any direction
desired. After adjustment, tighten the knob screws while maintaining the angle. The indicator is fixed to
the angle.
* Turning the knob screws may remove the knob screws. In such case, be careful not to let the indicator to
fall as it is free from its fixture stand. Such fall may result instrument failure from impact. Make sure to
take enough precautions.
Bottom view of the fixture stand

9
How to Use
Cautions
- No power switch is available for this instrument, therefore the instrument becomes its operation state
when connected to a power source.
- Connect to a power source only after completing the wiring.
- Please be careful not to confuse the wiring. Incorrect wiring may result in instrument failure.
- Do not touch the terminals while power is being supplied.
- Please use the input load within the standard specifications.
- Remove all electrical wirings before moving the instrument. Fail to do so may cause dropping of the
instrument.
- Make sure to select a proper type of AC adaptor in accordance with related standards and product
specifications when not using the accessory device that comes with the instrument.
- Make sure to put the terminal cover on during usage time in prevent from dust or an electric shock.
- Input a direct current with the range from 4 to 20 mA. Using the instrument outside of its range may
cause instrument failure.
1. AC adaptor
Please select an adaptor which meets following specifications when using another adaptor that was not
included in the instrument.
<Primary output>
Voltage : DC12V
Electrical Current : 1A
Polarity :
Plug diameter : outer diameter ø5.35mm, inner diameter ø2.1mm, length 9.25mm
2. How to use
(1)Check for the correct wiring and secure fixture of the instrument.
Refer to the 'Wiring method' and 'Installation method' sections of this manual for proper wiring and
secure installation.
(2)Insert the AC adaptor plug into DC jack from
the AC adaptor outlet.
The LED on the display will light up and the
instrument is in operation.
(3)In order to finish the operation, pull out the AC adaptor from DC jack. The display will turn off and the
operation is ended.

10
Alarm setting (optional)
Setting the thresholds for alarm will enable the instrument to alert with a buzzer or rotating warning light
when the displayed value is beyond either upper or lower limits.
* Alarm function is an optional function available at the time of purchase order.
· Alarm output is contact output of relay. Connect to an alarm device to use.
· Make sure the alarm device meet following specifications.
Rating : voltage resistance : 100 to 280VAC
Load current : less than 100mA
1. Wiring method
(1)Remove the cover and wire the terminal block. Re-install the cover after wiring. Refer to the 'Wiring
method' section for cover removal.

11
○ Wiring diagram
○ Terminal description
Terminal name
Description
T+
Temperature current input + Terminal
T-
Temperature current input - Terminal
H+
Humidity current input + Terminal
H-
Humidity current input - Terminal
AL Hi (℃)
For upper limit of temperature, terminal for alarm device connection
AL Lo (℃)
For lower limit of temperature, terminal for alarm device connection
AL Hi (%)
For upper limit of humidity, terminal for alarm device connection
AL Lo (%)
For lower limit of humidity, terminal for alarm device connection
* There is no polarity for terminals of alarm device connection.
T +
T -
H -
H +
AL Hi (°C)
AL Hi (°C)
AL Lo (°C)
AL Lo (°C)
AL Hi (%)
AL Hi (%)
AL Lo (%)
AL Lo (%)

12
2. Setting method
(1)Remove the cover and wire the terminal block. Re-install the cover after wiring. Refer to the 'Wiring
method' section for cover removal.
(2) Slide the alarm switch up or down to switch setting. Set limit is shown on the display.
* Use tweezers or a flat-blade screw driver to toggle the switch.
○ Enlarged diagram of alarm setting area
Switch for upper/lower limit of temperature
Switch for upper/lower limit of humidity
Volume for upper limit
of temperature
Volume for lower limit of temperature
Volume for upper limit of humidity
Volume for lower limit
of humidity
Alarm setting part
Switch for upper/lower limit
Display of measured value
Upper limit
Lower limit

13
(3)Turn the volume of upper/lower limit until the displayed value
matches an alarm setting value.
Turning it clockwise make the displayed value greater; turning
counter-clockwise make the value less.
* Do not let the alarm set value goes beyond the measurable range
(-10.0 to 60.0℃for temperature and 0.0 to 99.9%rh for humidity)
(4)Return the switch to the center position once the adjusted value is confirmed.
The display will switch to measured value display mode.
Maintenance
● Storage
Store the instrument in following ambient:
0 to 50°C and less than 80%rh (no condensing)
● Cleaning
- Do not wash or wipe this unit with alcohol, thinner, or other solvents. Use soft cloth to clean. In case of
tough stain, wipe it with a cloth that that has been soaked in water with a neutral detergent and tightly
wrung.
Volume for upper/lower
limit setting

14
Specifications
Product name
Temperature/Humidity indicator
Model
SK-M350-TRH-I
Cat. No.
No. 8091-52 (*1)
Display range
Temperature : -10.0 to 60.0°C
Humidity : 0.0 to 99.9%rh
Resolution
Temperature : 0.1°C
Humidity : 0.1%rh
Accuracy
Temperature : ± (0.2°C + 1 digit)
Humidity : ± (0.2%rh + 1 digit)
Sampling speed
Approx. 0.5 second
Display
7-segment red LED, character height: approx. 57mm
Usage ambient
0 to 50°C, less than 85%rh (no condensing)
Input connection
Terminal block
Input
Temperature : DC 5 to 19mA(-10.0 to 60.0°C) (*2)
Humidity : DC 4 to 20mA (0.0 to 99.9%rh)
Power requirement
AC adaptor 12V/1.0A (included)
Power consumption
Approx. 4.2W
Approx. 4.8W (with alarm)
Materials
Main unit (indicator): SCPP
Panel:Acrylic resin
Dimensions
Approx. (W)360 x (H)202 x (D)85mm (excluding projected part)
Weight
Approx. 3.8 kg
Accessories
Instruction manual, One AC adaptor
* Design and specification are subject to change without notice due to product improvement.
*1:Refer to the specifications of Cat. No. 8091-57 for alarm
*2:The current input range as a display range is 5 to 19mA, as the specifications are matched to the
output specification of our product, SK-RHC-I.