owmon: command not found

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On Debian possible default full paths are:

/usr/bin/owmon - from package: ow-tools

You may install the required package with command apt-get install {package}

Error in other languages:
owmon: bevel nie gevind nie
owmon: comandă negăsită
owmon: comando não encontrado
owmon: commande introuvable
owmon: command not found
owmon: käsku ei ole
owmon: không tìm thấy lệnh
owmon: komanda nerasta
owmon: Kommando nicht gefunden.
owmon: kommandot finns inte
owmon: komut yok
owmon: nie znaleziono polecenia
owmon: níor aimsíodh an t-ordú
owmon: no se encontró la orden
owmon: no s'ha trobat l'ordre
owmon: opdracht niet gevonden
owmon: parancs nem található
owmon: perintah tidak ditemukan
owmon: príkaz nenájdený
owmon: příkaz nenalezen
owmon: команда не найдена
owmon: командата не е открита
owmon: 命令找不到
owmon: コマンドが見つかりません